Signatories to sale deed

My mother, then aged about 19 years, had purchased a residential property in Mysuru, Karnataka during 1954 from an original owner of the same, through a registered sale deed. The original owner was a private person who was allotted the property during 1940 by the then CITB (City Improvement Trust Board), now MUDA (Mysore Urban Development Authority). My mother has three children, two sons and a daughter. She gifted about one third of the property to the daughter through a registered Gift Deed during 2002 and the remaining portion to her two sons (self and brother) through two separate registered Gift Deeds during 2012. Now, myself, the eldest son, and my brother (second son of my mother) want to sell our respective portions of the property, gifted to us by our mother, to a single buyer (or two different buyers depending on who offers the highest price). I have a wife and one son working abroad and my brother has a wife and one daughter working at Bengaluru. Please advise, who all are required to sign the two sale deeds, under Law, one between the intending buyer and self and the second between the intending buyer and my brother. Thanks and regards S G Siddesh