Is my brother's work as a lawyer, and his completion of administrative procedures for other cases without charge, considered as Zakat, or must Zakat be given separately?

Zakat has known conditions, including the money reaching the nisab, the passing of a full year (hawl) on it, and complete ownership. Volunteering for administrative procedures is not considered wealth by Sharia or custom, and therefore does not suffice for Zakat. Zakat must be calculated on money that has reached the nisab (equivalent to the value of 85 grams of gold), whether it is cash or trade goods, and it must be given out as money. As for volunteering to serve people, if it is in a permissible act, its doer will be rewarded by Allah; otherwise, it must be abandoned, and one must repent from it.