Gift deed

Dear sir /madam my self waseem my question is about gift deed agriculture land,my mother grand father did settlement deed to 3 daughter in law and 1 for his son, transfer year of 1974,in above 3 daughter in laws is one of my grand mother,and my grand mother had 2 daughters only, which is my mom and my aunt,so my grand mother gifted a agriculture land to my mother marriage occasion in year 1978 as orally which is she received from his father in law in year 1974,due to some financial reason we didnt registered in 1978 , the land is under my grand mother name but possession was in my mother since 1978 to till now,but the acceptance,registration and delivery had in year 2003 since 2003 the agriculture land is under my mother name now my aunt registered a complaint in year 2015 she wants a share in that agriculture land because she is asking this property belongs to her and my mother grand father property, my grand mother received a property in 1978 and it was under my grand mother name till 2002 after 2003 to till date is under my mother name,now my grand mother wants to revoke the land and she wants to equally distribute because of price hike since 40 years my mother cared and spend lot of money in that and also we consult with Islamic scholars and they said once a gift is gift it cannot revoke and we dont know what our Indian constitute says kindly request what need to be done as per constitution my question is revoke-able or non revoke-able thanks and regards waseem my email id [deleted]