Indigo Airlines : Up to 18% Off On Select Routes in Domestic Network
https://www.goindigo.in/campaigns/special-offer-on-select-routes.html
Apply Promo Code 6EDOM18 and get up to 18% off on all bookings made till 24th Aug for travel between 15th Sept - 30th Sept.
T^C:

This offer entitles you up to 18% discount on the base fare charges on select routes only.
The Promo Code “6EDOM18” needs to be entered in the promo code box on the payment page to avail the offer.
The discount is not valid on the applicable airport charges and government taxes.
Offer is valid on bookings made till 24th Aug for travel between 15th Sept – 30th Sept 2016 (both days included.)
The discount is applicable on one-way bookings for a travel for up to a maximum of (9) passengers.
This offer is valid only on direct flights across IndiGo’s domestic network.
Bookings under this offer are subject to availability.
This offer cannot be clubbed with any other offer/promotion offered by IndiGo.
Any participation in this offer will be deemed as an acceptance of the terms and conditions of this offer.
IndiGo’s decision with respect to all transactions in this offer will be deemed as final. IndiGo may at its sole discretion, extend, modify and/or withdraw the offer. This offer is being made purely on a “best effort” basis and is subject to force majeure conditions.
This offer is non-transferable, non–exchangeable and non-encashable.