मैं अकेला ही चला था जानिब-ए-मंज़िल मगर लोग साथ आते गए और कारवाँ बनता गया - Purnesh Upadhyay

I am reproducing the Official Text for You.
a) If a ticket is presented for cancellation more than 24 hours before the scheduled departure of the train cancellation charge shall be deducted at the flat rate of Rs. 70/- for A.C First Class/Executive Class, Rs. 60/- for A.C. 2 Tier sleeper class/ A.C. 3 Tier sleeper class/ First class/A.C Chair Car, Rs. 40/- for Sleeper class and Rs. 20/- for Second class.
(b) If the ticket is presented for cancellation within 24 hours and up to four hours before the scheduled departure of...
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the train, cancellation charges shall be 25% of the fare subject to the min. flat rate mentioned in clause (a).
(c) If the ticket is presented for cancellation within four hours before the scheduled departure of the train and up to :
Three hours, when the ticket is for a destination station up to 200 KM.,
Six hours, when the ticket is for a destination station of more than 200 KM but up to 500 KM., and
Twelve hours , when the ticket is for a destination station of more than 500 KM.,
after the actual departure of the train, cancellation charges shall be 50 % of the fare subject to the min. flat rate mentioned in clause (a).
Provided that for night train leaving between 21:00 hours and 06:00 hours (actual departures), refunds shall be admissible at the station within the time limit specified above or within four hours after the opening of reservation office, whichever is later.
(2) No refunds shall be granted at the station if the ticket is surrendered for cancellation after the expiry of the period mentioned under clause (c) of sub rule (1).
Note: (1) In the case of tickets issued for travel from some other stations refunds shall be admissible at the ticket issuing station provided that the ticket is surrendered before the schedule departure of the train from the station from where the ticket is valid.
(2) On a party/family ticket issued for more than one person, where some persons have confirmed reservations and others are on waiting list, full refund less clerkage charges is admissible for confirmed passengers provided that the entire ticket is surrendered for cancellation at the journey commencing station within four hours before the scheduled departure of the train and up to three hours after actual departure of the train.

(1A) Subject to provisions of subrule (2), no cancellation charges shall be payable if a wait-listed or RAC ticket is presented for cancellation up to :
(i) Three hours, when the ticket is for a destination station up to 200 KM.
(ii) Six hours, when the ticket is for a destination station of more than 200 KM but up to 500 KM., and
(iii)...
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Twelve hours , when the ticket is for a destination station of more than 500 KM.,
after the actual departure of the train except for a deduction of a clerkage charge of Rs. 20/- per passenger.
Provided that for night train leaving between 21:00 hours and 06:00 hours (actual departures), refunds shall be admissible at the station within the time limit specified above or within four hours of opening of the reservation office, whichever is later.
(2A) Where confirmed reservation has been provided to RAC or wait-listed ticket holder at any time up to the final preparation of reservation chart, such ticket shall be treated as a reserved ticket and cancellation charges shall be payable in accordance with rules mentioned above.
...and the same rule applies for E-Ticket too. Service Charges of IRCTC would also be forfeited in each case.