Enquiry about our problems.

Hello Sir/ Madam, Its a big issue we are facing now . my grandmother and his son have a joint property 7 acre 1.45 acre ( grandmas father in law property ) & 5.60 ( own purchased ) my grand mother had four children my mom and 2 younger sister and 1 elder brother my mothers brother was married and have two minor children ) my mother purchased 1.50 acre from his brother on 1996 with permission from my grandmother.After my grandmother death my mother and two sister given a share settlement for his brother . my mom 20 cent / and for both two sister 27 cent each ). and he go for a bank loan of about 10 lack. my moms brother met an accident on 2004 . he give promise to my mom that he will give 1 acre for his medical expenses ( the property worth 10 lacks for 1 acre ) my mom gave 7 lacks and his sisters made about 3 lack . my moms brother due to unfaithful of his wife he given his property to his sisters as follows to my mom 2 acre middle sister - 0.69 cent as joint and for the last sister 2 acre sole as a gift property . All the sisters given a promise to his brother that after the problem over we will settle the balance property of how much they given for medical treatment and expenses. my moms brother died due to liver failure last year . now my moms brothers wife tell that they cheated and buy this property ( she knew all the matters already ). she threatening to give back all the property . ( because of land value it going now 1 acre for 1.5 crore ) . my mom As promised ready to give 1 acre return and favor for his brother wife but she is not accepting . all the sister are not cooperate for land survey . look quite confusing but this is the problem . now the land is with my brothers wife control .not going out giving trouble.