Is it permissible to give Zakat to a retired military relative, 55 years old, married with one daughter, whose salary is 280 Jordanian Dinars, and who pays 100 Dinars for house rent, in order to help him purchase an apartment in installments by paying half of its price as a down payment?

If your relative owns enough to suffice him after paying rent for his house, then Zakat is not permissible for him, because he is not considered poor (faqeer) or needy (miskeen). However, if what remains for him is not enough for his needs and the needs of those he supports, then it is permissible for him to take Zakat from his relatives, as long as their financial support is not obligatory upon them.