PWD Property West Bengal

I m munna. My father had a shop on PWD land in the village which was capture by my grandfather and he demise in 1992 and in 2006 my sped and built a shop on that land and the electricity and trade license are in my name. But right now my uncle asks for a share on that shop. Is it possible bcoz we don't want to give share as it is a PWD govern land? Few people and my uncle threatened my father and give dhamkis. Is there any way to take legal action against them and not to give any share on that shop.kindly help us on an urgent basis.