My father's name matches with my uncle's name

Sir, I am 26 years old being raised by a single mother. I lost my father back in 2015,when I was pursuing class 12. He was an ex-servicemen from Indian Air force. Actually my grandfather had two sons. My father and my uncle. My father was elder one.Due to very pathetic financial crisis of the family my father was struggling to get a government job after the completion of his 12 class. And unfortunately my father's age limit reached and therefore was ineligible to apply for any job due to age factor. Now my grandfather, my father, and my uncle decided that my father will use my uncle's academic certificate to get a job so that he could help family in those tough times .he used my uncle’s certificate, cleared exam and joined IAF with my uncle’s name.Now after retirement my father purchased a plot in Punjab Mohali with his original name through voter ID card which we have only document with his originalname.And he passed away now we have death certificate on which my uncle’s name is mentioned even I along with my mother’s document posses my uncle’s name as father’s name and husband’s name respectively. Now neither we have documents of the plot nor do we posses any document with my father’s ORIGINAL name to claim the plot and in order to get it on my name or my mother’s name .my uncle has thrown us out of his house where we used to live as a joint family and claims falsely that he has a heir written by my father that the plot has been given to him.my uncle is doing a govt. job illegally using the ex servicemen quota of my father .my mother is not literate and had no idea about what was going on in the family by the time I grew up and found this discrepancies I lost my father and thereafter was threatened by my uncle that he can do anything against us to get that plot . Please help me with a possible solution to sort this all out .