Unity Dynamic Batching

public class test1 : MonoBehaviour {

    public GameObject prefab;

    void Start()
    {
        for (int i = 0; i < 100; i++)
        {
            GameObject tmp =  Instantiate(prefab) as GameObject;

            //Make sure you don't clone the material at runtime. If that's the case, then every object will have its own duplicated material.so they can't dynamic batching

            //For example, this kind of code causes a cloning:

            //renderer.material.color = Color.white;
 
            //In that particular case, vertex coloring is a workaround to change the color without duplicating the material.

            //Try to use only renderer.sharedMaterial or renderer.sharedMaterials.
            tmp.GetComponent<Renderer>().material.color = Color.red;
        }
    }
}