public GameObject[] allRings;
void Start ()
{
allRings = GameObject.FindGameObjectsWithTag("Ring");
}

void Update ()
{
foreach(GameObject ring in allRings)
{
float dist = Vector3.Distance(transform.position,ring.transform.position);
if(dist > ringDist)
{
ring.gameObject.SetActive(false);
}
if(dist < ringDist)
{
ringl.gameObject.SetActive(true);
}
}
}

  if (Input.GetMouseButtonDown(0))
         {
             RaycastHit hit;
             ray = Camera.main.ScreenPointToRay(Input.mousePosition);
             if (Physics.Raycast(ray, out hit))
             {

                 if (hit.collider != null)
                 {
                     Click(hit.collider.gameObject);
                 }
             }
         }

using UnityEngine;
using System.Collections;

public class MouseClick : MonoBehaviour
{

     // Use this for initialization

     static Ray ray;

     void Start()
     {

     }
     public delegate void MouseCliked(GameObject go);
     // Update is called once per frame
     public MouseCliked Click;

     public void mouseKlick()
     {
         if (Input.GetMouseButtonDown(0))
         {
             RaycastHit hit;
             ray = Camera.main.ScreenPointToRay(Input.mousePosition);
             if (Physics.Raycast(ray, out hit))
             {

                 if (hit.collider != null)
                 {
                     Click(hit.collider.gameObject);
                 }

             }
         }

     }
     void Update()
     {
         mouseKlick();

     }
}