don’t know about AMD, as we usually fly to S. India, but rare to not see Vistara as an option to BLR/MAA when looking at flights via UA.com. However, being relatively new west coasters, we prefer going via SIN now, as we can get a day or two in there, plus get some other options like being able to fly into TRZ, which is much more of a PITA via DEL/BOM.