What is the ruling on disposing of money and real estate acquired partially from unlawful wealth (gains from alcohol) that the questioner's father had taken from his deceased brother-in-law, and what is the ruling on benefiting from those gains over a period of time?

If your maternal aunt's husband's wealth is mixed, or mostly lawful, and he settled your father's debt from it by writing over half of his land and shop in lieu of the debt, then there is no blame on your father for owning them, nor on you for benefiting from their profits. There is also no objection to selling them.