In 2020 Indian Air Force revealed the plan to convert six A320ceo from ex. Air India to AEW&C aircrafts. Plans then have changed and they thought about converting ex. AI A319ceo and A321ceo.
Now more details are known. The aircrafts will be:
A321-211 MSN 3130
A321-211 MSN 3146
A321-211 MSN 3212
A321-211 MSN 3326
A321-211 MSN 3340
A321-211 MSN 3367
All of them will get a second APU as a power supply for the new equipment. The structural conversion will be carried out at TLS by Airbus. Final design will be similar to the Boeing 737 AEW&C.
The A319-112 VT-SCO has become a flying testbed.