Thank you all for tons of info. From Pahadi Dai's link:

Treaty of Peace and Friendship, Kathmandu, July 31, 1950

Article VII

The Governments of India and Nepal agree to grant, on a reciprocal basis, to the nationals of one country in the territories of the other the same privileges in the matter of residence, ownership of property, participation in trade and commerce, movement and other privileges of a similar nature.

Does this provision allow the citizen of Nepal to purchase property in India legally and establish residencey?

Thanks