What is the ruling on buying a house in Italy through an interest-based bank loan, given the absence of housing in Tunisia?

The remedy for your situation lies in sincere repentance, for Allah forgives all sins, and regret is a form of repentance. The usurious loan has no effect on the acceptance or rejection of your acts of worship. The house you purchased with a usurious loan is not forbidden for you to benefit from, because the usury pertains to your liability, not to the specific asset itself. We advise you to reside in Muslim lands to safeguard your religion, your family, and your children.