Seller of the land threatening to give the land back

I purchased a agricultural land from a Person , her husband signed the witness in the Absolute sale deed dated March 2018. Looks like someone approached her husband to pay him more money so he is asking the land back and we disagreed to give him back. The sale deed says the entire amount of the sale was given in cash. I have evidences of arranging the money bank statement gold loan and international funds transfer. He started threatening us,We filed a complaint in the SP office in the Anti-Land grabbing cell Krishnagiri Tamil Nadu. At the SP office when called, he is saying that we did not pay him the entire amount of the land and asking it back. Later he filed a complaint on me and my family that we did not give the entire money and he is sticking to the following conditions that he need partnership of whatever we do in that land or give back the land to him. Based on his police complaint he has given a copy of a CSR to the VAO and the Deputy Thasildar not to give the Patta for this land we purchased. After 2 months May 2018 he has files a case in the court that "me and This seller initially had a agreement to develop this land to make plots and sell on partnership and they were surprised to see a sale deed instead of a partnership deed. He is claiming that we cheated him, And he has pleaded the court to cancel the sale deed we executed. He has filed that he has the original document of the sale deed (which is false) we have the original sale deed copy. Does his case has any base ? Points: 1) We filed the first complaint that he is threatening us at the SP office. 2) He has given the statement in the SP office that we did not give him the entire amount. 3) Later he influencing the Local police station was asking us to settle the matter as per his terms. 4) The local station Constable was not ready to recorded our statement as per our statement, Luckily i have a recording where the conversation was recorded on my phone when I guessed there is something fishy. 5) He with this false acquisitions and a Police complaint has asked the Tasildar and the VAO not to Issue Patta. 6) Now has applied for a case in the court again on a false acquisition that we cheated him that instead of registering a partnership we executed a sale deed.