how to file for right of ancestral property by a daughter

My father and mother both owned huge holding of ancestral Agricultural land in Himachal Pradesh(170 Acres) located in three villages. He was survived by my mother and two brothers. One brother is now a High Court Judge. My father died in 1994 and the ancestral land he owned was transferred by my elder brother (then an advocate) using a fabricated Will in the name of both brothers. My mother also independently owned agriculture land in Himachal Pradesh and recently died few months back. My brother prepared a WILL and got it signed from her willing entire share of her agricultural land and immovable property(House) in Delhi in the name of both brothers. My brothers are not inclined to give me any share in the property.Please let me know if as a daughter I have 1/3 share in all immovable property owned by my mother. Do I give a legal notice first or file a law suit directly and where.