Hi caroline
as far as i can tell they dont use GCSE which isnt great but they do eval A Levels. Im pretty certain that you need to go via the FCCPT and get the schools and uni to send of the documents with the forms from the FCCPT so they can be eval and then they send them to the NYSED.
I dont think you can apply direct to the NYSED. Have a look at the FCCPT website and how to get licenced in NY.
Hope it helps. Good luck