Do you get off the F train at York Street or Jay Street-Metrotech to go 225 Cadman Plaza East?

There is no subway station in Brooklyn named "Jay Street-Metrotech." If you're planning to go to 225 Cadman Plaza East, the address of Brooklyn Borough Hall, you should get off the train at the York Street station for the F train. That subway stop is near Cadman Plaza, a short walk from the address you mentioned.