My grand father Land

Dear sir, My grand father having land is divided share from four members total 8.16 acres in three survey nos. My grand father maintain land of is share 2.04 and he expired on 2009. Then we decide last year to change the document to my father but now we came to know my grand father share land is three survey nos but two survey no land only in my grand father one of the survey no (total 2.65 acres) land 0.91 acres not coming under my grand father name. We traced the details we came to know my grand father share land is nominated guardian of is big father because of My grand father is father died in is small age. That guardian person transferred my grand father land to is wife name. But in old patta mentioned four name and A register is belong to my grand father name. In the chitta and new patta in guardian wife name. We seen in encumbrance certificate also my grand father not sold. But guardian wife sold to one third party and the third party person sold to the land for 5 members and they layout the land with DTCP and sold as a so many peoples. Now what can i will do with this case. I already collected the copy of documents sold my the guardian he mentioned in the documents my grand father as guardian. please give your suggestion. gokul