Goa
Officially, there are no nude beaches in India. Officially.
That said... Nude sunbathing gets mentioned in connection with at least four of Goa's beaches -- all in the northern part of the state.
Anjuna Beach is occasionally mentioned, but mostly with nostalgia. It is clear that nudity used to be tolerated at Anjuna. It is probably that European visitors sunbathe topless (with some discretion) and it is possible that the occasional leftover hippie actually strips off for a while and gets away with it. But Anjuna is more of a former nude beach than an active one today.
Arambol Beach is in a similar situation. Hippies discovered Arambol when it was unused and turned it into a stop on the trail. Today, "just a sprinkling of topless white females adorn the sands even as members of the Goa Police patrol the beach," according to a 2001 article by Goa Today.
They are Ozra Beach and Vagator Beach.
A dozen or so web sites publish this quote about Little Vagator Beach: "It's a free-and-easy mood at Little Vagator Beach where a young, hip crowd and nude sunbathing are the norm." It is unclear that the sites are related (except that they all deal with Goa and tourism) and it is impossible to tell which site the quote originates with. But MTV India independently confirms that Vagator is a de facto nude beach.
Mouthshut.com had this to say about Ozra Beach: Ozra beach is next to Vagator beach but not as easily accessible.This is also known as the nude beach as it does have foreign tourists “au naturelle” sun-bathing near the “Nudity Prohibited” sign!