Inheritance to sons

My grandfather has died intestate recently on Feb 2 2019. Though, he has not transferred the property ( land,agriculture fields to my father and father's brother,but he used to say this will be given to them only.since he is given every month maintenance by my father n father's brother .my father's sisters about (4 in number) are claiming for their share( according to Hindu succession act 2005) as my grandfather died intestate .they have been given dowry,earlier when giving land property to males(though not in paper) grandfather had asked to give some money to my father's sisters n were given too.my grandfather n grand mother had been being paid maintenance monthly charges for 5 years by my father .how can those sisters now claim equal share? Asking my father n father's brother to pay monthly maintenance doesn't it equal to his will of giving property to them( though died intestate).my grandmother still alive is proof of his interest to give property to make brothers.we cared them ,paid them for many hospital charges.now how can my father's sisters who are away n did not care my grandparents,just after his death claim legal share.this law doesn't seem to make justice for our case