Instantiate

public class LeaderBoard : MonoBehaviour
{
    
    public GameObject goRankBar;
    public GameObject goLastRankBar;
    public int count;
    public Transform rankBarParent;

    void OnEnable()
    {
   
        for (int i = 0; i < 50; i++)
        {
            GameObject rankBar = Instantiate(goRankBar, transform.position, Quaternion.identity);
            rankBar.transform.SetParent(rankBarParent);
            
            if(i == 49)
            {
                GameObject lastRankBar = Instantiate(goLastRankBar, transform.position, Quaternion.identity);
                lastRankBar.transform.SetParent(rankBarParent);
            }
        }
   }