How i can find position of left coner of the sprite.

Hello all friends using Unity. I make simple puzzle game. I just want to do it dynamically with c# script to divide sprite texture Texture of size 1024x768 is being cut into 4 equal pieces(4x4) I have code

          using UnityEngine;
         using System.Collections;
         
         public class TextureDivider : MonoBehaviour {
             
             public Texture2D source;
             public float NumberOfRows;
             public float NumberOfColumns;
             // Use this for initialization
             void Start () {
                 
                 GameObject spritesRoot = GameObject.Find("SpritesRoot");
                 
                 for(int i = 0; i <4; i++)
                 {
                     for(int j = 0; j < 4; j++)
                     {
                         RectTransform childRectTransform = this.GetComponent<RectTransform> ();
                         Sprite newSprite = Sprite.Create(source, new Rect(source.width / NumberOfColumns,source.height / NumberOfRows, 512, 512), new Vector2(0.5f, 0.5f));
                         GameObject n = new GameObject();
                         SpriteRenderer sr = n.AddComponent<SpriteRenderer>();
                         sr.sprite = newSprite;
         
  **//Here is the problem i need to get right positon of left coner of 
  //image on the screen to place first piece.**
                         n.transform.position = new Vector3();
                         n.transform.parent = spritesRoot.transform;
                     }
                 }
             }
         
         }