Should we get equal share of property in family dispute?

The property is owned by my grandfather, who has two sons and one daughter. The elder son has worked hard and constructed the house on ancestral property, supported the younger brother's family, included him in the business, and even paid for his marriage expenses. Now, my grandfather is supporting the younger brother and has stated that he will give all the property to him. The younger brother's family lives on the property and has a permanent address there, while the elder brother (my father) lives with our family in Mumbai, with a permanent address in Mumbai. Both brothers work in Mumbai, and the younger brother lives in Mumbai. We believe that we should have equal rights, and half of the property should be given to us. Please guide and provide a solution.