Require guidance

This query is related to property law and the juridiscation is state of Karnataka. My grandfather owned a piece of land in the Mangalore Taluka with five others. The RTC,short name for the document of title of the piece of ownership of particular land, includes names of 5 parties including my grandfather. Now 4 parties including my grandfather is dead and 1 party is alive but is not co-operative. Now my father wants to add his name as a legal blood related son in the RTC. But the lawyer is asking for death certificates of all deceased parties to add the name of my father. We do not know the family members of the deceased and on enquiring we came to know that one of the deceased party died in another country. One of lawyer suggested to put the matter in court but the result may come after endless years and the fees cannot be budgeted. Is there any legal remedy for this case.