Compensation for contribution

Sir/Madam, My father gave education to my younger brother up to 11th standard and after expire of my father I had given education up to 15th standard (I, e Degree) with technical qualification of shorthand and typing and after completion of education I had kept my brother in job in private company. I used to take case as my son, by his hardworking he had become manager in the organization. 10 years back he was died on road accident while going in car with his friends, case was filed in court against car owner and on insurance company, four years back, court delivered the compensation of Rs.30,00,000/- to my mother, he is unmarried & we are four brothers, In thirty lakhs only five lakhs are given as cash and remaining amount was kept as fixed deposit in nationalized bank for three years. My mother promised me that she will give me 50% of fixed deposit amount after maturity, because of taking care of my younger brother. Now she is refusing to give 50% amount because of my elder brother’s threat & pressure. Now my earnings are very less and I had two unmarried daughters, my health is also not good, passing through difficult time. In these regard, please guide me who to get 50% share amount in the court of law, for which I am thankful to you. Regards, Mohan