Ancestrol property

Sir we had a site of 3500 sqft which came from our four fathers. my grand mother was taken her share from her mother inlaws. other party sold their share and my grand mother kept the site as she no need to sell. when the other party come forcibly to come into our site my parents filed a case, after few years my lawyer said to my parents the other party is not attending to court so what use we can withdraw the case nothing will happen to us. without knowing his thoughts my parents signed on the papers he given them after three years the other party send notice to us that they sold that property to some other and asking us to vacant the site, we went to other lawer and he said that the last one cheated us. and given notice to both parties explaining our rights on site but they didnt took the notice, and this lawyer telling that dont let any one to come into our sight, no need to file case by ourself, as other party said sold this property to some one, already seven years are completed they registered to others,, what is the better option we can do this case, whether to wait for them or to file a case in court.