Property claim

Respected sir, my father first marriage 2sons.first wife was died during journey of govt bus accident.claim money from govt for accident.govt give three share to my father and 2sons.two sons share are used to higher studies.father share to buy some lands. Father married second one.they have two sons.after three years land with 32 coconut trees this land are registered to second wife name and build house 1bhk with father money.that time first wife sons age 15 and 7 Years go First wife son married now they are forced out from house. This land and house registered in my name said "second wife. Second wife said this land coconut trees with house are mine ,,not you and brother name She ask share on ancestors property for four sons.she give govt land (purampoke land) to build house to stay for both of you First wife sons are grown , education,and all expenses are fully hardly work to earn Father didn't support to first wife son Lot of struggle and problem facing in life please help me So we need proper guide to claim the property share to both of first wife son.