Passport expiring 30 Dec 2017-h1b under G221 process

Hello everyone,
Passport expiry in 30 Dec 2017, got a mail to submit passport for h1b processing now.
Should renew my passport now and submit for stamping? Or get stamped in old pp and renew later before to fly usa.
(I know 6month validity needed) but I attended the interview more than a year back n got g221.
which one to be followed?
Your advice are most valuable for me at this time. I got mail from uscis to submit the passport asap.

The passport renewal processes are simple, you may get your passport in a week or 2.

Go talk to them in the consulate, at the time of submission, you will get to know on what your options are. If they want a minimum 6 month validity passport, head straight to renew it.