回复：这样帮我哥留下行吗？

Are you concerned about whether your brother comes to US and unlawful presence (黑下来) will affect your status or something related?
I would like to say if nobody (especially 组团的人 in that文化交流团体)report this to USCIS, I do not think this will be a problem. But if the people in that文化交流团体 report it to USCIS or Chinese Embassy, your brother might be arrested and deported out of U.S.