mutation and affidavit

We are Christains. We are four siblings. Our mother died 30 years ago and left a will giving all of us siblings a share in her house though not equal share. We siblings decided divide the property evenly among us so we executed a notorised affidavit declaring that we have no objection if the property is mutated equally in our names and submitted this affidavit to the DDA for mutation. The DDA accordingly mutated the property equally in our names. I live outside Delhi and now after 25 years I asked my brothers to divide the property but they refused and said they will go as per will and not as per affidavit and mutation. I want to know what is the legal validity of the affidavit and mutation. Earlier I was told that the affidavit supersedes the earlier will. Please let me know my legal position if I go to a court of law