Just in case this is a serious question….
You can certainly kill a deer with a 9, but it’s very far from ideal, and may well be illegal in most places. The low power leaves little leeway for error in shot placement, and getting close enough for a precise shot placement would be difficult; it’s often difficult enough with a scoped rifle for many.
So it’s an easy “NO”.
If you’re trolling, a pox on you…..