unity instantiate child code example
Example 1: how to instantiate as child unity
Instantiate(obj, pos, rot, parent);
Example 2: instantiate gameobject as child
// 1. create game object
// 2. set its transform.parent property
GameObject child = GameObject.Instantiate(MyPrefab);
child.transform.parent = this.gameObject.transform; //or whatever gameobj will be its parent