What can I do if my step brother is claiming 50% share in my property?

I am the son of my father’s second wife.my father left his first family long back. Ancestral land was partitioned between my father and his brother, through un regist.partition. . When I became a major my father left us and after that he sold remaining 86 cents also with my sign to A. My step brother (first wife son) didn’t sign. A sold to B, B to C,C to D. With my money my father brought it from D upon his name and WILL was registered upon my name. My bed ridden father was living with me. After 2 months of purchase he passed away.My step brother lodged a murder complaint against me claiming 50%share. FIR not booked. police summoning me now and then in order to give him 50% share I stay in Hyderabad, 500 km away from my property. Since one and half year he is stealing coconuts from that land as he has police support. Many times I lodged a theft and tresspass complaint with police many times but of no avail. Kindly suggest