Raycast and Physics(Ragdolls): Update() or FixedUpdate()?

Hello!
This is the situation:
I got a Raycast (under Update() function) that when hit an enemy, launch an event that starts a method that enables all its colliders and Rigidbodies (that is, enable the ragdoll).
Should I put the Raycast under FixedUpdate()?

Plus, I noticed sometimes the ray doesn’t hit the enemy collider. It seems to fire through it.
Thanks!

all physics related code, (including raycast) should go in the fixedupdate