I have 3 kids

Honestly, 15 is such a tough age because they're trying to figure out who they are outside of you, so some pushback is pretty normal. I found that with my own teen, stepping back a bit and letting him have more say in things that affect him (like his schedule or room rules) actually reduced the tension, rather than clamping down harder. Maybe try to find one thing you can do together that he actually enjoys, just to keep some connection going, because sometimes the rebellion is more about feeling heard than about the actual rule-breaking. What kind of rebellious behaviour are we talking about?