grid.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Map : MonoBehaviour {
    
    //grid specifics
    [SerializeField]
    private int rows;
    [SerializeField]
    private int cols;
    [SerializeField]
    private Vector2 gridSize;
    [SerializeField]
    private Vector2 gridOffset;

    [SerializeField]
    private Sprite cellSprite;
    private Vector2 cellSize;
    private Vector2 cellScale;

	// Use this for initialization
	void Start () {
        InitCells();
	}

    void InitCells()
    {
        GameObject cellObject = new GameObject();
        cellObject.AddComponent<SpriteRenderer>().sprite = cellSprite;

        cellSize = cellSprite.bounds.size;
       
        Vector2 newCellSize = new Vector2(gridSize.x / (float) cols, gridSize.y / (float)  rows);
        cellScale.x = newCellSize.x / cellSize.x;
        cellScale.y = newCellSize.y / cellSize.y;

        cellSize = newCellSize;
        cellObject.transform.localScale = new Vector2(cellScale.x, cellScale.y);

        for (int row = 0; row < rows; row++)
        {
            for(int col = 0; col < cols; cols++)
            {
                Vector2 pos = new Vector2(col * cellSize.x + gridOffset.x + transform.position.x, row * cellSize.y + gridOffset.y + transform.position.y);
                GameObject cO = Instantiate(cellObject, pos, Quaternion.identity) as GameObject;

                cO.transform.SetParent(transform);

            }
        }

    }
	

}