What is the ruling on a company selling residential houses by installment, where the buyer pays monthly installments as "rent" until the price of the house is fulfilled, and then the house is registered in his name and becomes his property, knowing that the company raises the price of the house in exchange for selling by installment?

This transaction is an Ijara wa Iqtina (lease ending in ownership), which has permissible and forbidden forms. If the company's relationship with the bank involves usurious financing, then one should not deal with it until it refrains from usury, even if it practices the permissible forms of Ijara wa Iqtina. Installment selling is permissible if it adheres to Islamic guidelines, even if the price of the commodity increases due to the deferred payment.