Roger Joussaume in "Dolmens for the Dead" has a chapter on India.

5000 megaliths in a 5 mile radius around Brahmagiri - that's more than the Burren.

Some of them look mushroomy like Chun as well as the "shoe-box-with-porthole" style in your link.

He dates them from around 4000 years ago.

(Also grateful to the Joussaume chapter for adding "autochthonous" to my vocabulary - created without external stimulus. None of that diffusionist stuff for me.)