How to cancel and challenge a fraudulently executed gift deed

Sir, My uncle had fraudulently sold my granfather's property which was gifted to him along with building structure, stating it as vaccant land in the sale deed and the builder who purchased the same, demolished our common house building, and other structures of the house and raised new building by getting approval from the BDA authorities fraudulently and while the cases are being pending in the lower court, the builder again sold that property to another person because the I.A of all lower courts are vacated and now the third owner is again raising new construction by bringing new approval.How to make a stay for the construction going on and how to challenge the fraudulent sale deed ? At the time of the execution of gift deed the presence of house building and its valuation was mention but when my uncle sold the land along with the building property, he mentioned it as vaccant land to avoid the court fee fraudulently and after purchasing the builder demolished common house building.