Father property gifted to his son-in-law without son's approval

My father has transferred his purchased plot with constructed house to my sister's husband through gift deed. I came to know that it has been registered by my brother-in-law. Me and my wife served my father and mother for 12 years bearing all household expenditures and as we crossed 60 years, we could not serve my mother who was bed-ridden. At that time, my sister entered to serve my mother who was expired in Jan 2016. I came to know that, while serving my mother, my sister blackmailed my father to transfer his property or she would stop serving my mother. My father has no option and accepted without informing me. My brother-in-law forced him to transfer my father's house through gift deed and registered on his name. My sister also made my father to throw me and my wife out of our home, after my mother's death. Now, we are staying in a small home for rent. I have a son and daughter who are not settled and earning. I request you to know if there is any chance to claim a share in that transferred property, as we also served them for 12 years saving nothing for my children.