Property issue with my mother's brothers

My grandfather had 2 houses. After his death, 1 house was given to mother's two younger brothers & another house was given to my mother and grandmother by court. Now, my mother's two brothers staying in my mother's property(they are settled). My grandmother granted her share to my mother as settlement deed .. Is there any chance that my mother's brothers object and cancel the deed... My uncles are staying in my mother's share.. Do i have rights to collect rent from them?