Possession of Disputed Property

1) There were 3 residential properties in joint ownership of my grandfather and granduncle. My grandfather sold 1 property for marriage expenses of my fathers sister (Aunt). Now both of my grandparents and his brother are not alive. Out of 2 remaining properties, one is in our possession and one in possession of granduncle's son. 2) We don't know whether the property in possession of granduncle's son is accessed in his name or not, but they are claiming it to be. However they are not providing any proof for the same. For the property in our possession has names of both granduncles son and my father in city survey records. However both the parties are living in these properties for over more than 50 years. 3) Now recently government has come up with an order where front portion of our property will be taken by government for extension of road and the proceeds will be divided between two brothers equally. 4) My question is, since we are in actual possession of the property for over more than 50 year why should the proceeds be divided between two brothers equally? Can we claim full right over whole of the property in our possession? 5) If not, then since the matter relates back to more than 50 years, how can we ascertain whether we can maintain our claim on the property in possession of granduncle's son if he has not rightfully got accession of the property.