Is it possible to obtain a non-interest (riba-free) loan from Doha, and what are its conditions, to help those about to marry in Tunisia, and can benevolent people establish an Islamic bank in Tunisia to avoid interest-based loans?

Borrowing with usury for the purpose of marriage is not permissible. Usury is only permissible in a case of dire necessity that cannot be averted except by it. We advise facilitating marriage and reducing its burdens, and waiving luxuries. Islam encourages facilitating marriage and dislikes extravagance in all matters.