Who is the legal owner of property

Hi, my father brought the property in my mother name. I was groomed by my aunt from childhood till 13 years. Later I am a self made man. My father did not spent anything for me & my family. But he is so affectionate with my sister, she is deeded in silver spoon. Her hubby is in a govt job getting 80 plus salary pm. My sister is a professor getting handful of salary. One son is completed Engineering waiting for job other one is completing in one year. Has good property and building one more house in Chennai now. Their in law is ready to give their property to them to sell or to own. My father not done anything to me or my family members . Ex. Not even one saree to my wife after marriage. At the time of marriage he promised my wife that he will give site 2400 sqft to build a house. There was a small house on the site and he is taking the rent. We never asked. Recently he is not well and I got him to get good treatment and promised him to build a dream house in that site to make him live there and told him to enjoy one more floor rent for their expenses. I have a son . He is just 13 years. Wife health is not good. Doctor advised not to go for job. Still we are managing. I am just a graduate and Do I not have a permanent job. Life is difficult for me. When I spoke about the site. Now he says 50/50. Is it justifiable. He has one more house of the same area that was kept for my sister. I have no objection to give that to my sis. He is not keeping up his promises made to me and to my wife. Please advice