Hello,
I’m familiar with instantiating a prefab generally.
I would usually specify a Vector3 during the instantiation process, which would place it in those exact coordinates on the screen.
However it’s probably far better practice to add the item to the hierarchy it belongs to and specify it’s coordinates relative to it’s parent.
You could set the parent and local position after its been instantiated. Depending on what type you need to instantiate you’ll need to target the objects transform, or you could instantiate as a transform
public Transform parent;
public Transform prefab;
Transform clone = Instantiate(prefab) as Transform;
clone.SetParent(parent);
clone.localPosition = new Vector3(0, 2, 0);