Where you might be exposed to French letter on the radio? (6)
I believe the answer is:
quebec
I believe this is a double definition.
'where you might be exposed to french' is the first definition.
(Quebec's official language is French)
'letter on the radio?' is the second definition.
(Quebec is Q in the NATO Phonetic Alphabet)
(Other definitions for quebec that I've seen before include "French-speaking province of eastern Canada" , "Francophone Canadian province" , ".French-speaking province of E Canada" , "Largest Canadian province" , "Canadian city and province, French-speaking" .)