I also endorse the legal advice of expert Suresh Pawar. The daughter of A was the sole legal heir of A during the year 1983 soon on demise of A and thus on the death of the daughter of A, her legal heirs are legally entitled to inherit her estate.
You should first go through the documents which were used by B's sons to get the property mutated in their names. You should have obtained the copies of all such documents so as to challenge them as per law.
thanks for ur response sir. all the documents obtained and those documents registered by some others who were not related to ;A;s family. so if the legal heirs have to file a case for declaration of such documents null and void or any other way to file a suit for partition by one of the legal heir against another and the sons of B. which is best way dear Sirs?