Can we say: New York City is made up of five boroughs? Thks
The phrase 'New York City is made up of five boroughs' is grammatically correct. And as user86782 mentioned, 'New York City is divided into five boroughs' is also correct. To me, the first sentence is slightly less formal than the second sentence.
New York City is divided into 5 boroughs could also work.
I agree with the other two answers. "New York City consists of five boroughs" is yet another way to say the same thing.