How is the zakat calculated for a real estate deposit, by which the bank purchases properties and leases them for a period of five years, then sells them and returns the deposit with profit, along with quarterly profit distribution from the rent, given that the properties have not yet been sold?

As long as real estate is purchased for the purpose of sale, it is treated as trade goods, and its zakat (definition) becomes due after one Hijri year on the purchase price. The real estate is valued and added to cash and other trade goods, and zakat is paid on all of them together. As for the income from real estate, it is subject to a new hawl (lunar year) according to the Malikis, but it is preferable to add it to the value of the real estate and pay zakat on all of it together, for the benefit of the poor.