Property claim

Hello, my grandfather has a shop. Which is partnered by my uncle n father. Grandfather has passes away many yrs ago. In his will my uncle n my father are partners. My uncle is unmarried and aged 70 now. Father 74 My uncle is a lawyer with 30 yrs experience in civil law. My father is a school drop out. The shop is running till today. All the finance is looked after my uncle. And my father gets very little money like few thousands. He doesn't have a bank account. My grandfather left him 5 lac in 1986 which my uncle has access to. My father doesn't evn knw whr is tht money. The income from shop is very low.. My father and uncle use tht shop juss for timepass u can say. Witj veey little stuff to sell. With no workers. They do al work themselves. I can easily see a lot of potential in the place whr its located. Cuz its d main market. Im about to get married. I want to get settled. All we have is that shop. I was thinking of renting it. But as my father and my uncle is partners they don't want to rent it, nor renovate it or devlope or lease. So if we claim that shop? Or just the bussines. Its mygrandfather&co. Wen i asked for renting it because i have a right he said, come to me wen ur father is dead. He is a lawyer, with lot of experience. Im.feeling like hes conned my dad. What should i do?