Can i sell property which is on my grandfather's name

My grand father has two son (A and B- my father) and rwo daughters. He purchased one land and later he made building on that land and my uncle A was living with family(4 daughters). Now my grand father and my father B is no more. My uncle A still stays in the proprty and have made few more construcyion in that land. He is not ready to give my share in that land.Can i sell half of that land to someone without his consent? There is no batwara or will made between A and B. Pls advice.