Is money inherited from a father who worked as an accountant in a tobacco factory and received a social security pension from it, which the mother is currently receiving, halal or haram, and what is the legitimate solution if it is haram?

Manufacturing, selling, and buying tobacco are unlawful (haram). Everyone who assists in this is included in the prohibition. This includes working in accounting at a tobacco factory, and its wages are unlawful (haram) because they are for a prohibited benefit. The retirement pension is also not permissible to take unless it is a gift from the factory.