What is the ruling on advertising chat rooms or placing advertisements for them through my website?

The noble verse: (And cooperate in righteousness and piety, but do not cooperate in sin and aggression) necessitates urging cooperation in matters that benefit the Ummah and avoiding what corrupts it. Therefore, you must guide people to useful religious and worldly websites that are free from prohibitions, as this is a form of cooperation in righteousness and piety. It is forbidden for you to direct people to websites that promote forbidden things, as this is deceit and cooperation in sin and aggression. As for chats, if they contain forbidden things, it is not permissible to promote them. However, if they include constructive scientific discussions free from legal prohibitions, then there is no harm in promoting them, provided they are monitored.