Call and Render a Screenshot at Runtime,How do i render a sprite that was created at runtime (Screen Cap Question)

If you already have a reference to the Texture2D from your project that was made at runtime, then all you should have to do is create a sprite from that object using Sprite.Create and apply it as the sprite for the image component you wish to place the render to.

Take a look at this script for your reference, if you want to see it running add this component to an object in your scene, add an image somewhere in your UI to display the screen capture to and link it with the outputImage field in the inspector. At runtime press the Space key to see the output written in your image component.

 namespace PlayNice.UnityHelp
 {
     public class ScreenShotHelper : MonoBehaviour 
     {
         public Image outputImage;
         bool isCapturing = false;
         Texture2D currentCapture;
 
         IEnumerator CaptureRoutine()
         {
             yield return new WaitForEndOfFrame();
             try
             {
                 isCapturing = true;
                 currentCapture = new Texture2D (Screen.width, Screen.height, TextureFormat.RGB24, false);
                 currentCapture.ReadPixels (new Rect (0, 0, Screen.width, Screen.height), 0, 0, false);
                 currentCapture.Apply ();
             } 
             catch (System.Exception e)
             {
                 Debug.LogError ("Screen capture failed!");
                 Debug.LogError (e.ToString ());
                 isCapturing = false;
             }
         }
 
         void LateUpdate()
         {
             if (Input.GetKeyDown (KeyCode.Space))
             {
                 ScreenshotToImage ();
             }
 
             if (isCapturing && currentCapture != null)
             {
                 Sprite sprite = Sprite.Create(currentCapture, new Rect(0, 0, Screen.width, Screen.height), new Vector2(0, 0));
                 if(outputImage)
                     outputImage.sprite = sprite;
                 isCapturing = false;
             }
         }
 
         public void ScreenshotToImage()
         {
             StartCoroutine (CaptureRoutine ());
         }
     }
 }