Parents gave property to daughter in will can it be challenged

Mother is 1st holder and Father is 2nd holder of the Flat . In which we all live together hindu family . i.e... Mother, father , daughter ( divorced taken ) ,Son , son's wife and grandson . A Will is made by parents such that the total share and right goes to daughter then does the Son and the grandson cannot claim anything . Nomination also done in daughter name and given in society office . In such case is it that son and grandson is left with nothing and loose their right over property .