Threatened from one of my relative regarding property dispute.

I have parental property in muzaffarpur bihar and divided it between my four grandfathers by mouth with documentary proof and in records property in the name of their father. One of my grand father threatned me when i visited there regularly and said that all villagers favored me because i am residing here you dont have anything here. I only want that one room out of (total 4 room share) in my share there and 5-6 bigha other land take in my control and repir my room properly and also safe during my visit for any attack on me. What are the options available with me?