I think I'm the only one who ever posts here that's in favor of Air India, but I do like them and their prices for business are low. They are Star Alliances, so it doesn't hurt to check their rates.
I also love Turkish and fly them whenever possible and their prices are usually fairly reasonable. They're also Star Alliance.
As far as max miles, I don't know and others here probably have better ideas, but the best way to obtain the most miles is to stick with a single alliance. Look at any other flights he might have in the next year and base your decision on prices, but more importantly - does the airline/alliance in question go to ALL of his destinations next year?
There is no point earning 10-20% more miles on a trip to India if he has to jump around for future trips and scatter his hard-earned miles everywhere.