Issue with assigned land and my mother's brother threats

Sir In 1972 my maternal grandfather registered agricultural dry land of 75 acres in the name of his three daughters including my mother with 25 acres each. . My mother recieved the title deed in year 2014..till then she was unaware of the title deed of 25 acres of land on her name Now when all the proof are in the name of my mother,even after that my maama (my mother's brother) is farming in tat land.. and as now when we went to take over the land with authority of being owner for farming he is threatning us We r not getting police protection too for that ... This is one issue One more issue is that Since the land was registered in 1972 and land ceiling act came into force 1975.. the 75 acres of land is assigned to 3 sisters of 25acres each in title deed and pass book .. during survey of the land VRO says that 10 acres of land out of 75 is been considered as assigned lands under land ceiling act ... My mother asking how can u assign the land which is not above the limit...acc to act if dry land is above 54 acres then it will come under ceiling act whereas 75 acres divided among three and now its 25 acres each.then how it can be assigned ..and fr dry land its 5 acres is considered as assigned land..how 10 acres is considered.. We are facing difficulty with land even being owner of land Sir can u please suggest how to defend and resolve the above two issues