My aunt came to fight for a house after my father died.

As the legal heir of your father, you are the first heir and your aunt is the second heir, so since you can inherit, your aunt has no right to claim your father's inheritance right;

As the legal heirs of your grandparents, your father and your aunt are at the same level. At that time, your grandparents died, and your aunt could share the property with your father. If it is not more than two years since your grandparents died, then your aunt still has the right to win the lawsuit of your grandparents' inheritance.

Suppose your grandfather died after your grandmother died, then if your grandfather has been dead for more than two years, and your aunt has not offered to share the property left by your grandfather during this period, even if she did, she will not be supported.