I know I have seen articles saying you can get a pre-paid SIM on arrival at DEL and BOM airports - is there the ability to get this on arrival in Chennai (MAA) as well? Flying from SIN, if that makes a difference.

also, if available, are there multiple or just a single vendor for this. Where we are going (village in S. India), BNSL is really the most reliable carrier, so hoping we can get a SIM from there. Apparently Airtel is available in the area too, but less as reliable, so that could be an option as well.