In Indigo there is a Flex option which I don't know what it stands for ?
Apparently it stands so that one can reschedule the flights as well. But I was told at the gate that full fare would be needed to reschedule the flight which is/was confusing.
To take an example -
Let's say I have a flight on 10th December 2018 from Cochin to Pune, (COK to Pune) 6E 337 . I already booked the flight for say INR 3000/- which includes the flex option (INR 1000) . See charges
Now I want to prepone my travel to 3rd December 2018 . I was told that I may have to again full charges which seems absurd suggestion. This happened at a recent flight and I had to buy a new flight ticket altogether and then come back and cancel the flight.
Just for reference I saw this news item on the same topic 3 years back.