What is the ruling of Sharia on benefiting from a property that the state has seized from its original owner due to outstanding taxes, whether by remaining in a commercial premise that has been allocated, or by residing in an apartment that has been purchased?

It is not permissible to seize anyone's property except by a legitimate right. The non-payment of taxes does not make it lawful for the state to usurp a person's money. If the state has a right, it should resort to the Sharia (definition) court, which will arbitrate between them. If the Sharia court rules in favor of the state regarding some of the man's property, there is no harm in the state taking it. However, taking people's money without a legitimate basis is forbidden, and it is not permissible for anyone to take this usurped money, buy it, or benefit from it.