Placing tiles around the mouse position

I have this code to add a tile to the world when the mouse is clicked in the editor screen, my problem is I would like to make it place in a circle radius around the mouse so I can put tiles in large areas. Here is the section of code that places a tile at the moment:

 if(e.isMouse && e.type == EventType.MouseDown && e.button == 0 ){
             GUIUtility.hotControl = controlID;
             e.Use();
             GameObject gameObject;
             Transform prefab = grid.tilePrefab;
             if(prefab){
                 Undo.IncrementCurrentGroup();
                 gameObject = (GameObject)PrefabUtility.InstantiatePrefab(prefab.gameObject);
                 Vector3 allign = new Vector3(Mathf.Floor(mousePos.x / grid.width) * grid.width + grid.width / 2f,
                                              Mathf.Floor(mousePos.y / grid.height) * grid.height + grid.height / 2f, 0f);
 
                 if(GetTransformFromPosition(allign) != null){
                     DestroyImmediate(gameObject);
                     return;
                 }
                 gameObject.transform.position = allign;
                 gameObject.transform.parent = GameObject.Find("Level").transform;
                 Undo.RegisterCreatedObjectUndo(gameObject, "Create " + gameObject.name);
             }
         }

Anyone got a clue on how to do this ? Thanks.

EDIT: Each tile is 8 units wide in case that matters to anybody