In magic hexagons , the number in the middle is the product or multiple of the adjacent side.
Move anticlockwise, in the first box we shall get 11 × 9 = 99.
In the second box we shall get 11 × 6 = 66.
In the third box we shall get 6 × 17 = 102.
In the fourth box we shall get 17 × 7 = 119.
Now move clockwise, in the first circle we get, 108/9 = 12