After the Indian Army, I feel the Railway department is the one which does not disclose anything to the general public. It is very difficult to find out on what basis, the tickets are allotted and on what basis the waiting list tickets are confirmed. Many times, eventhough, I had booked the ticket very early, My ticket was not confirmed. Where as, others' ticket got confirmed eventhough they had booked just few days before. I could gather some information on this, but, still there is much more that is hidden.
In each train, the seats are allotted to different railway zones based on some hidden criteria. In each railway zone, the major cities get some quota based on some other hidden criteria. And, there are different waiting lists like, (General) Waiting List, Pooled Quota Waiting List, Remote Location Waiting List, Request Waiting List etc., which are not trivial to understand.
Break Journey
If you are traveling from A to B, and if you are not getting confirmed ticket, then break the journey at a major station between A to B, or at a station where the railway zone changes just before or after. Book two tickets, one from A to that station, and another from that station to B for the same train. That may have more chances to get confirmed ticket. When compared to long journeys, short journeys have more chances of confirming.
If you are traveling by Charminar express from Chennai to Secunderabad, and if you don't get confirmed ticket, then try from Chennai to Gudur and Gudur to Secunderabad. This has more chances of getting confirmed ticket, or less waiting list number than Chennai to Secunderabad. Chennai is in Southern Railway zone, and Gudur and Secunderabad are in South Central Railway zone. There are different quotas from Gudur to Secunderabad and Chennai to Secunderabad. The quota from Chennai to Secunderabad is used up very soon, where as the quota from Gudur to Secunderabad is relatively not used up so soon. So, there are more chances of clearing. You can apply the same logic for Tatkal as well.
Extend Journey
If you want to go from Chennai to Vijayawada by Howrah Express, it is very difficult to get a confirmed ticket unless you book atleast a month in advance. Even tatkal also would be filled up within half an hour to one hour. But, if you book the ticket from Tambaram to Vijayawada, then you will get the confirmed ticket easily. That train has different quotas for Chennai and Tambaram. Many people travel from Chennai and it is difficult to get confirmed ticket from Chennai. Whereas, from Tambaram, not that many people travel, so, you can get the confirmed ticket easily.
The extension of journey is useful, only if you can get a confirmed ticket at the time of booking. If you get waiting list, be very cautious. The waiting list from small stations would be cleared in different way, and the waiting list won't go down like how it goes if you have booked normally. In case of this type of booking, if I get waiting list ticket, I will not depend on that, since, it has very less chance of clearing, because of less quota.
This is mainly useful in case of Tatkal quota. For Tatkal quota, in the main line, the quota would be filled up by 8.15 - 8.30 AM on the opening day. Where as, if you extend the journey, you would get some more time.
Book two tickets, in case of RAC or Waiting List
At the time of booking, if the status is waiting list or RAC, and if you would like to travel comfortably, then book two tickets per person. At the time of chart preparation, if that becomes RAC, then two passengers would be allotted one berth. So, you would get a berth. Before chart preparation, you can check the status, and if it is confirmed, then you can cancel one. After the chart preparation, if both are confirmed, then it is a long procedure to cancel just one ticket.
Tatkal for the trains that start after midnight
If the train that you are traveling starts little after midnight, and if that station is not the starting station, then for the previous station for which starting time is before midnight, the tatkal quota would be opened one day before your starting station. You can book the ticket three days before (instead of the usual two days for Tatkal) from the previous station.
In case your starting station and the previous station have the same quota for the journey, then you must book from the previous station (unless, there are vacant berths even after one day). For example, Chennai express departs from Ongole for Chennai little after mid night, and from Guntur, it departs little before midnight. The tatkal quota is opened for Guntur one day before Ongole, and both have same quota to Chennai. On the first day, if the quota from Guntur is used up, then there will not be any berths available by the time tatkal is opened for Ongole. In this case, if you want to travel from Ongole, you have to book the ticket from Guntur three days before.
If you are booking the ticket at the railway counter
If you are booking ticket for which the starting station is in different railway zone, and if the ticket is in waiting list state, then think twice before booking it. I feel, it is just waste of money. It will not be confirmed so easily. If the starting station is in the same railway zone as the booking counter where the ticket was booked, then it would be given much higher preference than the ticket booked outside the railway zone. Once, I booked a ticket at a booking counter in different zone one month before and it was not confirmed. Another person booked in the same zone (for the same train and route), just 4 days before, and it was confirmed.
I don't know how it works online. When I booked wait listed ticket, I got all the possibilities like Waiting List, Pooled Queue Waiting List (PQWL), Remote Location Waiting List (RLWL). What I observed was, except General Waiting List, everything else would clear very slowly. So, if you get waiting List no.of 10 in RLWL or PQWL, don't be happy. At the time of chart preparation it may stop at 2 or 3, where as general waiting list 40 may be confirmed.
If you want to travel by somebody else's confirmed ticket
If the chart has not been prepared for that train
Then book another ticket for that train for yourself, even if the waiting list number is very big. With that ticket, you can board the reservation compartment. Make sure to mark the confirmed ticket with TTE (may be by somebody else, and not by yourself). With the waiting list ticket that you have, you can travel without any problem in the reservation compartment, and with the confirmed ticket, you can have berth.
If the chart has been prepared or even the waiting list tickets are not issued.
In this case, you need help of somebody else who is traveling in the same compartment. Take a general ticket, and make sure that, TTE is not aware that, you have a confirmed ticket. Mark the confirmed ticket by somebody else, and don't appear to TTE at all. In case, if you have to face TTE, face him at a different berth and ask him for a berth. He will say, there are no berths available (unless you are traveling on Diwali night). When he is not around, just go and sleep in the exact same berth that was allotted to that confirmed ticket. Don't try to change the berths unless those were also marked by the TTE and the actual ticket holders of that berth are around.
Technically, in these cases, TTE can twist in whatever way he wants. If you have only a general ticket, then TTE can impose fine of Rs.250 and the reservation charges for that route. However, if TTE is allotting a berth to you, he would collect only the reservation charges (and some bribe). If the TTE comes to know that, you have a confirmed ticket of somebody else, then, he will ask you for the maximum fine. The TTE just won't listen, if you ask him to allot the berth that was confirmed on the other ticket. Finally, you will be end up paying bribe which is more than the technically possible fine.
You are an educated person. Don't you know that it is computerized?
If you start arguments with any of the railway officials on anything on the tickets, their reply would be the above only. But, the fact is, till the time of chart preparation, the railway officials can change many things. They can give you a confirmed ticket, they can confirm your waiting list ticket, they can change the names of the ticket, and they can change the boarding station from a completely different place. All are possible. But, you cannot approach them directly. You need to go through the appropriate brokers for that.
TTE can do, if you are ready to pay enough
After the chart preparation, TTE can arrange the berth, if you are willing to pay enough. Almost all the long journey trains have atleast three TTEs for different compartments. If the TTE is allotted to the compartments which have the quota of tickets from the starting station to the last station, then he may not be able to help you that much. But, other TTEs would be able to help you, if you are willing to pay enough.
Delay in Train Timings are as Designed in Small Railway Stations
When the railway department publishes the timings of the trains, the most important requirement for them is, no train departs before the published departure time. It is also not possible for the trains to travel with the uniform speed everyday. When they publish the timings, they fix the timings at the important stations by the average in the last few months. Between the two important stations, the (published) timings are distributed in such a way that, it appears that, the train travels very fast for the first 75-80% of the journey, and goes very slowly for the rest of the 20-25% of the journey. By that way, the train never departs before the published departure time. If the train reaches an important station little early, they can let it wait till the published departure time. Whereas, they cannot do that for small stations. That's why there is discrepancy in the published times and actual times at small railway stations. This also gives the impression to the passengers that, initially, the train was late, but the train driver managed to reach the destination on time. Where as, everything was as designed. If you have to board a train at a small station, and if you are late, don't change the plan of your commute immediately. Check whether the train had already left from that station or not, and then only change your plan.
I think one can easily do a Ph.D. on the Railway reservation system.