$20 money order would be fine.
Please read carefully on Consulate General of India - New York's website to make sure that they DO NOT have any kind of formula, or anything similar to that.
For example, I read on one of the consulate's website where you have to like give $20 for the mailing fee, but you have to add like $1.00 to every additional members of the household that is beyond 3 or more people.
So, again, please read Consulate General of India - New York's website correctly.
I am not affiliated with the TRAVISA either, but I sent $20 mailing fee to get my O.C.I, as well as my new 'U' Visa affixed to my American Passport.
I sent in my $20 mailing WITH the O.C.I application processing fee, so I DO NOT have to send the mailing fee no more since Consulate General of India - Houston has it in their possession.
My O.C.I have NOT been approved yet by the Consulate General of India - Houston, but hoping to get that thing approved by the early August, or at least in month of September 2011. I sent the O.C.I application in January 2011, and got acknowledgment in February 2011. Since then it is still in ''Under Process", and now we are now in month of July.
good luck, and congratulations on getting the O.C.I cards printed, and in the hands of the New York Consulate.
Another suggestion is that if you live near by, then you can just drop off your, and other family member's passport DIRECTLY to the Consulate General of India - New York. If you could not go, but know someone in the area, or a friend that drives down there, then given it to them so they can drop it for you to the Consulate General of India - New York.
Again, good luck, and congratulations on getting the O.C.I cards printed, and in the hands of the New York Consulate.