Opinion on a property rights

your grandfather property become personal property after partion....so they can dismissed it to anyone they want....but....if your father was alive or was in womb......at or before the time of partition......then your father has equal right in the property ( before partion the property should be ancestors property and your father was alive at time or before partion )

The property is not ancestral. As such, the grandfather can dispose the same at his discretion. Your father is only legal heir to the property, if any, left intestate after his lifetme.