بسم الله الرحمن الرحيم
(Fatwa: 1087/1066/N=11/1438)
Yes, the money which you have given to your friends and brothers as debt and you are sure to receive that money back and you are sahib-e-nisab in view the total zakah money then its zakah is wajib on you, and you may pay its zakah once you receive the money. And if you pay the zakah of those money each year and do not wait its repayment then there is no harm in it rather in some aspect it is better.
فتجب زكاتها إذا تم نصاباً وحال عليه الحول ، لكن لا فوراً بل عند قبض أربعين درهماً من الدين القوي كقرض الخ (الدر المختار مع رد المحتار ، كتاب الزكاة ، باب زكاة المال ، 3: 236، 237 ، ط: مكتبة زكريا ديوبند).
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband