Is it permissible to give a brother one percent of the sale value of an inherited house because he found the buyer?

Your brother is entitled to the customary brokerage fee in your country if he is known for brokerage, acted as a broker for you, and brought the buyer. However, if he is not a broker, the default is that he is a volunteer, unless you agreed with him beforehand on a fee. In that case, he is entitled to what was agreed upon; otherwise, he is entitled to the customary fee from the total price before it is divided.