Gift deed

My Grandparents have three children 2 sons and one daughter and one of them passed away 20 years( My father) Since then we have been living with our grandparents and Uncle. My uncle very conveniently by emotionally blackmailing and mentally pressuring my Grandparents took all the property as a gift deed and we got only 25% of the share whereas he took 75%. I knew about his intentions but in order to maintain peace in the house and out of respect, I never said anything. But in 2016 I recorded my Grandmothers conversation in which she has expressed her desire to give me the property she wanted, but uncle do not agree. She passed away without making any will. So whatever was on her name got transferred to uncle, myself and my Aunt. However, my grandfather gave me his share and told me on the phone that he was forced previously to give the property to my uncle. I had recorded that conversation in which he said that uncle made my grandmother mad and pressurized her. He also said that is very upset as he felt cheated and betrayed. He was afraid of my uncle due to his old age and could not help me. Now I have all the proof that with me i.e phone call recordings etc. I also have audio proof in which my grandmother expressed her wish that she did not want to give anything to my aunt as he already her too much for her daughter's wedding and education. My aunt is also holding her share and want the money. What can I do to this injustice and greedy family members?? My grandfather is alive, but he is too afraid of my uncle and he is 80 years old. What is my legal right of this injustice?