My grandfather passed away young, leaving behind his property which my father has been managing and living in ever since. He built a house on the land. Now, my father’s sister is claiming her share. Since my father took care of her needs and marriage after our grandfather’s passing, is her claim justified? If so, what percentage of the property should be given to her?

Under Indian law, your father’s sister is entitled to a share of the property inherited from your grandfather, regardless of your father’s support. The exact percentage would depend on the nature of the property (ancestral or self-acquired) and the specific provisions of the applicable law (Hindu Succession Act or Transfer of Property Act), requiring consultation with a lawyer for a definitive answer.