Getting instantiated clone's coordinates from the same script

In my program, I'm supposed to create an instantiated particle-system, and then translate it to the location of a certain clone. However, I have found no good way of doing this; the idea I had was called "obsolete" by Visual Studio, and I don't know how (Or if) I can use GetComponent <>() in this situation either.

Here's the code I have now:

(To instantiate the Clone)

     Rigidbody rb;
     rb = Instantiate(fallingObject,position,rotation);
     rb.name = "Clone";  

(To move the particle-system to it's location)

  private void OnCollisionEnter(Collision collision)
     {
         if (collision.gameObject.name =="FallingObjects")
         {
             Destroy(this.gameObject);
         }
         if(collision.gameObject.name == "Ground"||collision.gameObject.name == "Player")
         {
 
             Rigidbody rb = gameObject.rigidbody;
             Destroy(Instantiate(particles, rb.position, rb.rotation));
             Destroy(this.gameObject);
         }
     }

Again, my main issue is with the "Rigidbody rb = gameObject.rigidbody;" line of code; it says that it's obsolete and that there's a better answer than just that, however I need to get an instantiated clone, so GetComponent<>(); wouldn't be able to pick up the precise clone that I need to do that to.

Thanks a million for your help