بسم الله الرحمن الرحيم
(Fatwa: 1254/H-300/TH=10/1434)
You should know the amount of share and profit on the date on which zakah becomes wajib on you and then pay the zakah. But if there is some mistake, it can be paid later.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
