Brother harassing me and my family for property

My parents owned landed property fm fly income on mother's name measuring 2400"each in Chennai & Bangaluru. Father died in 2007 & 4 Br's only. Mutually 4 Br's agreed equal share of 1200" each at Chennai & Blr on choice. In 2000, II & III opted Chi & regd their shares. In 2010, IV regd his Bangaluru share. All empty ground & mother's gift. Yet to get mine, Mother, wife & 2 sons r staying where 2 storay house is constructed, I am CGS employed in UP. Mother, III & IV are threat to my family. stating, I have no rites owned by mother and vacate the house, reason being I left Blr for employment. Blackmailing my family in my absence for police complaint on torching mother & not vacating. Misguiding her to create embarrassing situations in public, to gain old age sympathy & force able vacating. II & III stay in Chi, while IV stay away in Bangaluru. I beg for help & guidance for amicable settlement to get ride of family hardship & mental fear.