بسم الله الرحمن الرحيم
(Fatwa: 1078/835/H=9/1434)
If you have sold the house to your mamani you will have to pay zakah of its price though you have intended to purchase a house in other city after receiving the payment.
If you did not sell, or the case is different, please, submit the question again.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
