How can I have an access to the rigidbody component of each instantiated object?

In Game Controller script, I have instantiated a stream of balls falling from top of the screen. I stored the references to these instantiated objects in a list whereby I can access it using listname[index]. .How can I have an access to the rigidbody component of each instantiated object? Here is my script. Where should I add the rigid body codes to access the rigid body components of the spawned objects. Here I have limited the action to setactive (false) of the list elements. What I wanted is to change the velocity of list elements.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class ballmove : MonoBehaviour 
 {
     public GameObject enemy;
     public Vector3 spawnPosition; 
     public float spawnWait;
     public float startWait;
     public bool stop;
     int i;
     List<GameObject> abc;
 
     void Start () 
     {
         int i = 0;
         StartCoroutine (waitSpawner ());
         abc = new List<GameObject> ();
         
     }
     
     void Update () 
     {
         if (Input.GetKeyDown (KeyCode.RightArrow))
         {
             abc [i].SetActive (false);
             i++;
         }
             
     }
     IEnumerator waitSpawner () 
     { 
         yield return new WaitForSeconds (startWait); 
         while (!stop) 
         {
             GameObject thisobject = Instantiate (enemy, spawnPosition, gameObject.transform.rotation) as GameObject; 
             abc.Add (thisobject);
             yield return new WaitForSeconds (spawnWait); 
         }
     }
 }