Often people make reservations for seats or berth to travel by train. Many times you get reservation in RAC or waiting list. All waiting lists or RAC tickets are confirmed when another passenger can cancel their ticket.
Whether your seat or berth has been confirmed or not, you can see on the website of railway after put PNR number of your ticket. If your seat or berth has been confirmed then the website will tell you the status of your ticket as per the PNR number. If your waiting list ticket has been confirmed then you will not know the number of seat or berth at that time. You will know the seat or berth number when the chart of reservation seat of the train will be ready.
Chart preparation time is 4 hour before the departure time of train.
You will be assigned seat or berth number only after this chart is prepared. It may or may not be able to confirm your RAC ticket or waiting ticket.
If your RAC ticket is not confirm, then you will not get a berth for sleeping on RAC tickets, but you will get a seat for sit in reserved coach. If you want, you can cancel the RAC ticket. For this, the Railways will deduct some fees and return the remaining amount. If your waiting ticket is not confirmed after prepare chart, then you travel by same train and can sit in that class which class ticket you have. But if you have booked a e-ticket online, and if your waiting ticket is not confirmed after chart preparation, then your waiting e-ticket will be canceled automatically, and your booking amount will be refunded in your account.
After the chart is ready, it gets stopped online reservation in that train. But at many major stations, there are some reservation counters on which reservation tickets are also available for that day. If the seat is vacant in that train, then you can reserve a berth or seat from the counter, even if the chart is prepared.