My wife is Chinese and here on a green card. Can we bring her brother here on a 6 months (or so) temporary visa and can he work (unskilled) here

Hello. She can invite him and he can try and get a tourist visa. He cannot work here as a tourist, even in a restaurant. His stay will only be good for 6 months if he approved for the visa at the Embassy. There is no "cook visa" that he would qualify for in order to work.