Answer :
It depends. But if you use....
2 cubes per rectangle you can get 9 rectangles
3 cubes per rectangle you can make 6 rectangles
6 cubes per rectangle you can make 3 rectangles
2 cubes per rectangle you can get 9 rectangles
3 cubes per rectangle you can make 6 rectangles
6 cubes per rectangle you can make 3 rectangles