Instantiate GameObjects inside a collider

 GameObject area;
 Public GameObject item;
 
 void start()
 {
 area = GameObject.Find("area");
 Instantiate (item, area.transform.position, transform.rotation)
 }

Do ensure you have the item prefab alloted to the item gameobject. This piece of code will instantiate the item gameobject at the position of the area gameobject, i. e., Within its mesh renderer provided the item gameobject is obviously smaller in scale. @ratchetunity