The airline said it is on track to operate more than 1,650 flights, up from around 1,500 flights on Saturday.
In a statement, IndiGo said its on-time performance improved to 75 per cent, from 30 per cent a day earlier.
The carrier also announced a full waiver on cancellation and rescheduling charges for all bookings made till December 15.
What triggered the crisis
IndiGo, long known for its punctuality and scale of operations, has acknowledged that it failed to adequately prepare for the rollout of stricter Flight Duty Time Limitation (FDTL) rules for pilots that came into effect on November 1.
The revised regulations mandate tighter restrictions on night flying hours and weekly rest, forcing airlines to restructure crew rosters.
IndiGo’s inability to realign its schedules in time triggered a cascading impact across its network, resulting in crew shortages, widespread delays and large-scale cancellations over the past week.
The Civil Aviation Ministry has directed IndiGo to complete all refunds related to cancelled flights by 8 pm on Sunday and to ensure that all delayed baggage is delivered to passengers within two days.
Airlines have also been instructed not to levy rescheduling charges on affected travellers.
IndiGo said it is handling all refund-related issues “on priority.”