What does “PNR number” mean?
PNR number in full is Passenger Name Record number. It is a ten-digit number that identifies an individual as a potential passenger of the IRCTC. It shows you that you have booked a ticket and that your ticket is being processed by IRCTC. Your ticket is placed on a waiting list and moved up depending on the availability of space on the train. A ticket holder will get a space on the train when his number of waiting list gets to one and a space opens up in RAC.