Benaami

My father bought an agricultural land in the name of some of his relatives (real brother and brother-in-law) in 1988. My father died a few months ago. After that, the relatives made a notarial agreement with me stating that this land was purchased by my father with the consent of relatives and the property owned by my father. Whenever they transfer it, they will keep some part of the land and give the rest of the land to me without any consideration. And the relative is just a benami accountant and my father has been in possession since the beginning. But now the relatives are withdrawing due to bad faith in their mind and have also sent the notice of cancellation of the agreement, in which it is written that because this land is benami, this agreement is void from the beginning and we did not know about the benami law. That is why there is a possibility of legal action against us, so we cancel it.So can I make a declaration suit on the basis of possession and how to avoid being benaami.