India cash machines are confusing. After a lot of trial and error I seemed to have less problems with ICI cash machines but even then you seemed to have two types of cash machines “national” enabled and “international” enabled. So even different cash machines in the same branch gave different results
What I figured out was that the cash machines seem to have 2 modes of operation. Pit card in and remove the card and it will attempt to use the magstrip. If you put it in and leave it in, it will attempt to use the chip, but you have to wait 30 seconds or more for the chip to pick up.
As I was there on business I gave up in the end and switched to using my credit card in India and had zero problems.