"mod means modified. it means not all the passengers on the ticket are cancelled except few."
------------
it does not mean that sir. Even all the passengers may be modified and there may have been manually upgraded or downgraded or there may be a change of date involved of all the passengers in pnr(both preponement and postponement). I would also like to mention here that this change in class is manual and not automatic and almost equivalent to cancellation of ticket. The only difference is the prs ticket you will receive will have...
more... written "modified resvn ticket" over it. You have to fill just one reqstn form at prs(as opposed to 2 in case of cancellation and re-resvn) and present it with original tkt at prs superscripted with the terms"request for modification of tkt" just as we superscript tatkal tickets.the charges for cancellation and modification is same.the last thing is you cant give berth choice(ub/lb/mb,etc) in case of modified ticket. Thats all.
Thanks