The Railway PSU has already tied-up with budget carrier GoAir and have sold about 100 tickets through this scheme in the past one month.
"We have also entered into an understanding with SpiceJet under the scheme and plan to rope in other domestic carriers too," said IRCTC spokesperson Sandip Dutta.
However, the scheme applies to tickets booked at least three days prior to the date of the journey. The flight tickets would be made available only for the day of the train journey or a day after that.
IRCTC would be sending emails to waitlisted passengers who seek to avail the benefit under the scheme.
Passengers booking train tickets right from sleeper class to AC classes can avail the facility, Dutta said.
"For such passengers, the airline ticket would be competitively priced and cheaper by as much as 30-40 percent," he said.
The airlines would be placing their unsold tickets with IRCTC, a move that not only promises a boon for the domestic carriers but an added option for the passengers in reaching their destination without having to abort their trip.
With an average seat factor of about 70 to 75 percent, most of the domestic airlines fly with about 20 percent seats empty in their plane and IRCTC plans to make the best use of it.