Need Legal Guidance

I have about 4 acres of agriculture lands and I am residing a little far away from it. Because it is very far away from where I stay and work , my visit to that place is on yearly once or twice basis. A portion of 1acres 20 guntas was acquired by the Deputy Commissioner for grant of House plot for weaker section of soceity and we had no objection to it because we were served notice and intimated by the DC office. Grants and right certificates were issued to various villagers with regards to the above acquisition. Of late it has come to my knowledge that the Panchayat Development Officer and Executive Officer of Panchayat Office have colluded and issued additional rights certificates and made arrangements for issue of E-khathas to villagers in the balance 2 acres 20 guntas of lands which is not acquired officially and also we did not get any notice or intimation . The balance lands are not officially acquired by any government agency and nor Deputy Commissioner. Based on the above , alleged rights certificates issued by PDO ,some villagers have constructed houses on it....Can the legal team please guide what is proper legal steps I have to take immediately to protect my property.