Can you play volleyball with a torn acl if you use a brace or something?

Yes: You can play volley ball with a brace, but no brace is 100% effective. Playing with or without a brace places your knee at risk for additional damage if you have a fall, unexpected contact, or other injury while on the court.

Possbly: If the brace prevents the shifting sensation of the knee during participation then one could play. It is not a guarantee that more damage may occur while you play, particularly to the meniscus.