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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.
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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.