I think in any country I visit, even in my own country, tipping is generally expected. It's not like we're pressured to tip or anything like that, but it's safe to assume that those who give us service at least expects some tip from us. And even in India, drivers, waiters, porters and bellboys do still need tips.
I personally tip everyone that provides me service, whether he's a driver, a salon personnel or a tour guide. And if he did excel in his service, like a tour guide that made me learn a lot or a driver that helped me find the best local restaurants, I'd tip them more than necessary.
As others have already pointed, you can use these guides in tipping in India. If you rent a driver for multiple days, I'd say tipping him everyday between Rs 300 to Rs 600 would be good enough. If you rent a driver just for a day, then consider tipping him Rs 300 to Rs 500, depending on how helpful he has been.
I would also suggest for you to tip higher than normal if the person went out of his way to help you. This way, you have compensated him enough and he's more likely to extend that kind of service to other passengers.
I hope this helps!