To be suitable, they have to be Ph.D.s who have published in their field of expertise. They don't have to be currently affiliated with a university, but it helps, especially if they're at major institutions and hold important chairs. If you haven't involved such consultants from the beginning, you should do so from this point on, if at all possible. Budget in travel and expenses for one meeting between you and these scholars. Otherwise, do all your business by mail.
Academics are easier to deal with that way.
Otherwise, the producer better be an Indian. Run your idea lucidly by an NEH program officer by phone. If you don't hear an expression of interest, forget it. NEH has some pretty indifferent program officers and some responsive ones as well. My favorite is Virginia Field who loves radio.