Ownership of land as a cause of family dispute

One of my uncle (father's brother) was absconding for last 30 years and now treated as dead. my two uncles (father's brothers) have got the land registered in their own name, which was in their name jointly with the absconding brother of my father. however, mutation not done yet. for this purpose, they have furnished fraud affidavits / witnesses. they even did not disclose that they have five sisters and two more brothers to avoid sharing the land with them. now my query is :

(1) what legal remedy is available with me? should i file suit for partition for the land in question? (2) what is the appropriate forum - district court or dy. commissioner of the district? (3) or should i move application before tehsildar court? (4) what can be done so that they (my father’s brother) do not become lawful owner of the land, and the land is shared among all brothers and sisters of my father? the land in question is agricultural and is located in ambala, haryana.