Section 15(2) in Railway Passengers (Cancellation Of Ticket And Refund Of Fare) Rules, 1998
(2)The refund of difference of fare under sub-rule (1) shall be granted at the destination station on production of the ticket along with a certificate from the conductor or the guard or the travelling ticket examiner of the train giving particulars of the ticket, number of the coach and stations between which the air-conditioning facility was not provided, and is presented within twenty hours of arrival of the train.
