Be careful:
Pot was criminalised in 1985. It is true that the ban is not enforced very rigidly, and another derivative of the cannabis plant, "bhang", is (I believe) legal in some parts of India and widely used on festive occasions. But pot is illegal and can land you a 10 year jail term. Legally, I believe, it is not a lesser offence than using the harder drugs. Here’s a 12 year old article, but I don’t think anything has changed since then.
Confirmation here.
The Dish 