Our first experience with the trains wasn’t so glamorous.  (SEE STORY HERE)  We ended up on a 16 hour cross country “van” ride that seated 7, but there were 9 of us.  This time we had tickets for an overnight train from Bihar to Varanassi.  It was a big scramble to get on the train.  The stop at the station was seriously, 3 minutes.  When the train stops, you have 3 minutes to find your car, your seat, a place for your bags, and get settled in.  Our friends helped us board the train and helped stow our luggage.  This was nice, but not as helpful.  We didn’t know where they put our bags.  The other challenge is that we are in class 3C.  It was a sleeper car with 3 bunks on a side.  The middle bunk folds down for a back rest for the lowest seat.  Anyone with top bunk tickets will sit on the lowest seat until it is time for bed.  Or you could just have random people sitting on your bunk, they may not have even had a reserved ticket.  If you were lucky enough to get a lower bunk, you won’t be able to use it until everyone is off. 
One of our lower bunks was occupied with 3 Indian Army guys.  We weren’t going to ask them to move.  We learned a lot.  We did find a place to sleep.  We learned that Class 2C is better; less bunks, less busy, for only a little more money.