Father property issue

I have 1 younger sister she is married for last 25 yrs and 1 younger brother who is also married and both are well settled. They have there own houses. After 1 year of my marriage my father brought me into there own house, because my husband is not working and we are having plenty of quarrel.After some time I started working and supporting my family financially in the meantime we had done my younger sister marriage and on 10 sep 2000 my father expired and after 2 years my mother got pyrolysis attack and in the period of that 2 year(i.e. before pyrolysis) I had done my younger brother marriage. my mother have signed declaration on rs.10 paper, stating that after her dead the given premises should transfer to my name as I was taking care of my mother and after my younger brother marriage he is not interseted in taking care of mother and left the father home with his share. my sister and brother had provided me NOC and taken there share. After that I had taking care of my mother and all here needs for 10+ years and on Dec 2011 my mother expired. In 2017 feb I haved renovated my house spend 6 lakhs one day I brother camed to my house and stole some of my document (father retirement book, NOC affidavit) and now he started asking for the share in the house. can you please advise. Note : The house is still in name of my father and I have all the required original paper with father and mother dead certificate