Family agreement to inherit property

My widow mother died in '97 leaving a prime real estate property which was on her name at Bangalore. Her Will was duly probated by which half the property went to her only son and the other half over which he had the right to give it to his 5 siblings as per her wishes.This property was under litigation since '89 .all the six inheritors continued the case on the same line as the deceased mother from civil to High and Supreme court.In 2012 the case got solved , the family won it.Since many years three of the siblings live in the house while three including the son live in other cities , the son in US. Three sisters demand for 1/6th. share.Two of the sisters are willing to go along his wishes. My brother is willing to divide the real estate/ proceeds into seven equal parts one each for five sisters and retain 2 for him. How can this be done legally thro' a Family agreement? He has not till date transferred the property on to his name as the litigation was going on and all six children fought the case as legal representatives/ inheritors.