I am a 60-year-old woman, and I have a 55-year-old brother. We are the only siblings of our parents. My father's property consists of his own earnings and inheritance from his father and grandfather. Until 1987, all properties were purchased in my father's name. My father passed away in 2021 due to COVID-19 without transferring or bequeathing his properties. When I approached my brother to claim my share of the property, he initially refused and now claims that our father wrote a will in 1986, leaving the entire property to him. This will is completely fake and unregistered. Although my father was uneducated, he was able to sign his name. Upon investigating with friends and family, it appears that my brother forged my father's signature with the help of an artist skilled in imitating signatures. He added one of our distant uncles and another cousin as witnesses, who signed the document.
How can I prove that the will is fake and that my father did not sign it? People say unregistered will are acceptable by law and I have no option. Please help me