What should I do with the inheritance my mother left, which consists of money in an interest-based bank, gold, and real estate, knowing that she did not pay zakat on her wealth, and that some of the sources of this money were illicit, such as drugs, and I am not sure about the source of the gold?

Usurious gains from the bank are to be spent on general Muslim welfare. The principal, however, is permissible (halal). To distinguish the principal from the gains, one can refer to the bank for a detailed account statement, or use one's best judgment and probability. Inherited wealth, if its source (permissible or impermissible) is unknown, is considered permissible by scholarly consensus. Permissible wealth is subject to zakat, which should be estimated to the best of one's ability. Impermissible wealth is not subject to zakat. If the heirs are males and females, the male inherits the share of two females. It is advisable to refer this inheritance matter to a Sharia court or consult with scholars.