CSHARP

oncollisionenter

private void OnCollisionEnter()
{

}

oncollisionenter

void OnCollisionEnter(Collision collision)//Make sure to put this out of Voids
    {
        if (other.gameObject.tag == "Object") 
         {
             Debug.Log ("Collided");
         }
    }

oncollisionenter

OnCollisionEnter(Collision collision)
{
	ContactPoint contact = collision.contacts[0];
    Quaternion rotation = Quaternion.FromToRotation(Vector3.up, contact.normal);
    Vector3 position = contact.point;
    Vector3 relativeVelocity = collision.relativeVelocity;
}