Every day the Indian Railways is transporting millions of people and tons of freights. People are booking the tickets and they are allocated with a seat and a berth. But when the allocation is over booked the customers are given RAC status which is Reservation against Cancellation or Waiting List tickets. Thus people always opt for advance booking because if they book early there are chances to get confirmed seats and berths but if there is any delay in booking the tickets that may come in RAC status or Waiting List status.
The Waiting list and RAC tickets come in two different categories; fully wait list tickets and part waitlist and RAC tickets. In case of part confirm / RAC / waiting list if on one PNR number there are more than one passengers and any one of them is having a confirmed seat or if some are in the waiting list and some have the confirmed seats the names of all the passengers booed on such PNR will be there on the chart. In that case a certificate can be obtained from the TTE in the train regarding the matter of non - travelling of the passengers in the waiting list. The passengers can even obtain the refund there after.
Sometimes it may happen that the passengers are not willing to travel before the preparation of the chart in that case the cancellation can be done online at the same time. The passengers can even contact IRCTC for the cancellation of the tickets. IRCTC will refund the exchange as per the extant refund rules but that will be executed after the verification of same from the railway offices of the particular zone.