If you want to modify or cancel your booking, here’s what you should do:

a. Booking modification

As per Indian Railways/IRCTC rules, modification of ticket such as changing the traveller name(s), gender, train, travel date is not allowed. In such cases, you are advice to cancel your original ticket and rebook a new ticket to meet your needs. However please note normal cancellation charges will apply for cancelling your original ticket.

b. Booking cancellation

Train booking cancellation is allowed online on Paytm upto chart preparation time of the train. Post chart preparation time, you will have to file TDR. However please note that online cancellation is usually not allowed during IRCTC maintenance window daily between 23:45 hrs and 00:20 hrs.

To cancel your ticket:

1. Open your Paytm app, go to "My Order"
2. Locate the appropriate booking
3. Open the booking
4. Click on the “Cancel Ticket” option here and choose the travellers
5. Now click the “Submit” button

Please note that cancellation is not allowed in certain cases such as “Current Availability” booking. Additionally you may not be eligible for any refund in case of cancelling a Tatkal ticket. 

For complete information on the cancellation charges/rules, refund policy and TDR filing guidelines, please refer to this document of IRCTC/Indian Railways.