Property dispute with brother

My father bought a plot in, Chennai in the year 1972. He built a house in the plot by taking loan from his office in the year 1972 &1974. The members of the family were his wife, myself one son and another daughter. He younger sister was mentally retarded from childhood itself and could not do her work by herself and needed assistance. I got married in 11.11.1983. In the year 1989, my father retired and he built the first floor of the house out of his retirement proceeds. At that time, I was with them from 1988 to 1989 as I gave delivery to my daughter in 1988. My father and mother were taking care of the mentally retarded sister. My brother was overseas and didn't take care of them any time. Even when he was in Chennai for sometime, he lived separately in his Flat.I was residing in the first floor of the house with my parents & sister when my family came to Chennai on my husband’s transfer from Delhi and I was taking care of them when l was in Chennai from 1995 to 2001 till l shifted on my husband's transfer. My father died on 22.11.2003 and I took my mother & mentally retarded sister to my house as my mother couldn't take care of my sister alone. My mother was receiving the rent from the house for their expenses. I was taking care of them till 2010. In between she lived in Chennai for 1 year from Dec 2004 to 2005 and during that period my son was with them taking care of them. My mother became a dimentia patient in 2009. For 2 months during 2009, they were taken by my maternal uncle eyeing for swindling the property but sent them back as they came to know that the property can not be taken as it was selfearned by my father and my mother was a dimentia patient. As per doctor'advice,my sister was admitted in a home at Chennai in Dec 2009 because l was not able to take care of two insane patients and my husband got cardiac problems. I admitted my mother in a dimentia centre in Dec 2010. My mother died on 17-07-2011. My sister died on 23-01-2014. From 2009 August the rent from the house was received by brother and I also allowed due to problems from uncle and the expenses for mother and sister was met out of the rent. Now after the death of my sister, when I ask for my share in the property, he refuses and even informs that it is his house. He also states that he has built the first floor of the house which is a lie whereas it was built out of my father's retirement proceeds during 1989 . His statements are lies and he has not done anything for his parents who suffered with the mentally retarded child throughout their lives.l, my husband and my children suffered so much mental and physical tortures, sufferings & sacrifices due to keeping my mother & sister for so many years. My brother didn't ever share at least 1% of the same throughout his life. My mother & father informed that the house is to be shared between me & my brother after the death of our mentally retarded sister. My father left no will. They have even left the original title deeds with me only. The relationship with brother was ok till recently. He even executed a POA in my husband's favour with which he even executed a sale deed for him. During his visit to our house during Nov 2013 he has taken all medical bills incurred by me for mother & sister when they were with me. The house was of 2 floors and there were 2 tenants. I came to know that the tenant of firs floor vacated on 26-03-2015, I came and occupied the same on 30-03-2015. He through a third person filed a case informing that the third person has entered into a rental agreement with my brother thru, a POA holder and paid rent advance. He obtained an inerim injunction stating that he is living in the first floor( where I am living) and shall not be disturbed by me. We through advocate moved he court and informed that the court has been defrauded thru fake papers. The injunction was vacated on their submission that my brother is ready for a settlement with me. At this juncture, how can I get me legal share in the property? As it is, I am living in the first floor of the property. Regards,