Is it permissible to work in a store, part of which is leased out for selling pork and its derivatives, and is it permissible to lease out this part in the first place?

It is not permissible to rent out a place for the sale of prohibited items such as pork, because it involves aiding in sin and aggression. Allah says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." If the lessor knew that the lessee would sell pork, he has erred and must repent, and the rent is not lawful for him. If he was unaware of this, then the lease remains permissible, and he must strive to terminate the contract or hold the lessee accountable and not renew the contract. As for working in the shop in a permissible trade separate from the prohibited items, it is lawful. However, enjoining good and forbidding evil is obligatory for the seller and for your uncle if he does not seek to terminate the lease, according to the Prophet's saying (peace be upon him): "Whoever among you sees an evil, let him change it with his hand; if he cannot, then with his tongue; if he cannot, then with his heart—and that is the weakest of faith."