OnCollisionEnter without disabling isKinetic

Hello. I need script like :

if(collision.gameObject.tag == "tag"){
doSomething;
}

The problem is that I can’t disable isKinematic in rigidbody(my prefab is falling through the floor). By far there’s no “isTrigger” overthere, and fixedUpdate with target finding is lagging too much. Any idea?

If your rigidbody is kinematic, set the collider to be a trigger and use OnTriggerEnter() instead.