Mothers ancestral property

Respected Dear sir my mothers ancestral property my grand father had only 3 female childs after some years he adopted his borther son (not leagally ) my grand father died some desieas. my grand mother made property as schedule A and schedule B in 1968. schedule A property for my grand mother and her 3 female childs. schedule B property for adopted son (not leagally ) and for his sons after the years in 1981 adopted son (not leagally ) taken some of schedule A properties without her knowledge ( she was uneducated , just thumb) after some years again some properties taken same as above... when i saw kraya patra ( sale deed) in that my grand mother only saled all properties to clear her laons and burdens without knowing what they written in kraya patra she put thumb . in 1989 one of my mother sister filed petition in civil court banaglore, after that settlement out side the court, some property given to my mother sister and that decreed in court . so, in that time yhey written on decree "In so far as the remaining properties are concerned, the defendants 2( 2 sister of my mother) and 3 ( my mother) who are sisters hereby relinquish and release whatever right, title and interest they have in the remining schedule properties infavour of the 4th respondent defendant ( adopted son )as they have been adequately compensated by the 4th defendant ( adopted son) by mutual agreement and they make it very clear that hereafter the 4th defendant (adopted son) shall as owner enjoy the remaining schedule, properties exclusively absolutely and free from any interferenve by them." they taken thumb and signatures of my mother. now, i asked property share with aopted son sons, they were were refusing to give share of property , i asked only how much property as given to my heleder mother 1991 through court. that much give,,they refused to give . i filed petition in court for share. for my statement, they submitted above documents (1968 sales deed, 1981 sales deed and 1991 compensated (nothing compensated) to court .. idont know what to do now plz guide sir