According to IRCTC and Indian Railways rules in 2026, you cannot cancel a confirmed e-ticket online for a standard refund once the chart is prepared (usually 4 hours before departure). However, you can still seek a refund by filing a Ticket Deposit Receipt (TDR) online. For confirmed tickets, TDR must generally be filed at least 4 hours before the scheduled departure if the passenger does not travel. If the train is running more than 3 hours late, you can file a TDR for a full refund without cancellation charges. For RAC or Waitlisted tickets, the deadline is usually 30 minutes before departure. It is important to note that filing a TDR does not guarantee a refund; the request is forwarded to the Zonal Railway, and the final decision is based on the specific circumstances and extant refund rules.