Is zakat obligatory on a residential home, a rented inherited property, and a plot of land purchased five years ago, knowing that there are debts being paid in installments? And what is the percentage of zakat due in this case?

A house designated for dwelling is not subject to zakat. The same applies to the value of a rented house. Zakat is only obligatory on the rental income if it reaches the nisab (minimum threshold) and a hawl (one lunar year) has passed over it.

If a plot of land is purchased with the intention of trade, zakat is obligatory on it, just like on trade goods. Its nisab is equivalent to the value of 85 grams of gold, and the amount of zakat to be paid is 2.5%. If the value of the land intended for trade is less than the owner's debt, then there is no zakat on it. If its value is more, and after deducting the debt, no nisab remains, then there is no zakat on it. If a nisab remains after deducting the debt, the remainder is subject to zakat. However, if the land was not purchased for trade, there is no zakat on it, but if it is sold, zakat becomes due on its price.