Is Zakat obligatory on the deceased's wealth that reached the Zakat threshold when the heirs receive it, and does its reward go back to the deceased?

Zakat is obligatory on the debts owed to your deceased brother if they reach the nisab (minimum threshold) and a hawl (one lunar year) has passed on them. It must be paid from his estate before its distribution. If the debts are owed by a wealthy person who acknowledges them, then zakat is paid for all past years. However, if they are owed by a poor person or a procrastinator, then zakat is paid for one year after their collection. The deceased is rewarded for the intention to pay zakat, even if he was unable to perform it.