Can farmer claim to buy the land plowing since sixty-five years

We are doing agriculture on a land for 65 years.sixty-five owner has given the land to us.but it is not on the record. but his son has sold the land to someone else,for without informing us. now they want to sell land to some other person.what can we do.can we are eligible to case a file in court.we are saying that if u want to sell the land we can purchase the land at which u have bought from that person. What shall we do?