Secrets of PNR NO................
First 3 Digits:-
They tell us from which PRS the ticket has been booked.
The PNR Numbers' starting digit does not depend on the PRS from which it has been booked.
It...
more... actually depends upon: Zone of the Train, w.r.t. starting station of the train.
2,3: NR, NCR, NWR, NER
4,5: SR, SWR, SCR
6,7: NFR, ECR, ER, ECoR, SER, SECR
8,9: CR, WCR, WR
e.g. If a ticket is booked in Rajdhani Express (Mumbai to New Delhi), as the starting station is Mumbai, PNR will start from 8.
The subsequent 2 digits detail specific PRS.
Last 7 Digits
They are randomly generated numbers. They represent no information.
PNR number lasts minimum 9 month as the TDR filed can take maximum of 9 months. It then flushed out. (Normally)
After a year, the same PNR number can be generated.