Preemption

My mother purchased a piece of land from a recorded owner, X, in 2023. The land was originally recorded in the name of X’s deceased father. Before the purchase, the land was transferred to X’s name after a gift deed was executed by X’s siblings in favor of X. A warison certificate was issued by the local panchayat, listing X’s siblings as the heirs. All these heirs signed the gift deed for the specific land parcel, transferring ownership to X. Following this, my mother purchased the land from X, and the record of rights and mutation were completed in her name. However, we recently received a court notice from a person, Y, who has filed a preemption case against my mother and X, demanding that the land parcel be transferred to his name. Y claims to be a co-sharer of the land, even though neither he nor his deceased father is listed as an heir in the warison certificate. Furthermore, Y and his deceased father do not own any adjoining land. They also do not own any land on the plot number which we bought from X . We have learned that Y’s name may have been excluded from the warison certificate by X, possibly because Y attempted to purchase the land at a lower price, while we paid a significantly higher price. Y has now filed a preemption case with consideration money. We are unsure how to proceed. When we purchased the land, all the heirs mentioned in the warison certificate signed the gift deed to transfer ownership to X. X became the recorded owner, and we purchased the land legally. What steps should we take now?