About agreeculture land

Here relations are very difficult to understand .so please read carefully?.......first to end....my grandfather has 2 son and 1 daughter.i am son of his daughter. Here my grandfather has 10 bigha agreeculture land.My grandfather got that agreeculture land by will from her second great grandfather.actually at that time my grandfather's father and mother was died in accident. grandfather's great grandmother done two marriages.she was marriaged second time after her first husband died.And my grandfather' father was son of her first husband.after , second marriage of my grandfather's great grandmother , she got 2nd child as a daughter by second husband whom we call now our grandfather's great grandfather. My grandfather's great grandfather(grandfather's great grandmother's second husband) had willed that 10 bigha agriculture land to my grandfather and neglect his own daughter(my grandfather's aunty(bua)). He only give 1 bigha to his daughter (my grandfather's aunty(bua)) by Varsai.At that, time my grandfather's father already died.so my grandfather got that 10 bigha by will from his second great grandfather. The land is located at city area and it's price now in crores. *so I have fear that my grandfather give all the land of 10 bigha to his 2 sons by will and neglect my Mom as his great grandfather neglect his daughter ? he can do it ? *This agriculture land is now called ansectral or not ? *my mom can stop execution of will in future if my grandfather will make that type of will ? * and if my grandfather want to sell that land now and give all money to only 2 sons , at that time of sale my mom have right to stop selling of that land ? please carefully read this whole question first to end...and reply .i want to clear my mom's fear about that land ?