Can a hindu widow gift in-laws ancestral property?

On what basis you have alleged the property as ancestral property? What is your status? Why the transfer was not challeged when property was transferred in your Aunt's name? It seems that property was belonging to your uncle and after his death the property was transferred in your aunt's name, hence, your aunt being the owner of property has rightly transferred the same to her brother. You have no right in the property nor you have any right to challenge the gift.  

Your aunt's brother is agricultrist (Farmer)? if he is not farmer then how can she gift deed registered and how can transfer this property in your aunt's brother name. 

who is transfer this land in your aunt name?

Ancestral Agriculture land in your father and uncle name?