DL on their 772LR is better than CO's BF product for the non-stops to BOM. For MAA you are going to connect, either in Europe or in India to Kingfisher (IT) and likely require an overnight at BOM/DEL to do so.

Starting in a couple weeks you'll be able to transfer points freely between your DL and NW accounts so you will be able to redeem on Jet. That being said, the ability to make those transfers isn't really out yet so no word on just how easy/functional it will be in a couple weeks when the functionality comes out.