Josh,
If you've got a current foreign class-1 medical, a valid pilot license and a file number, then you can get a waiver.
All you need is to obtain an NOC from the DGCA medical wing. For that you've to write to the DMS with a copy of your licenses. Don't forget to add a PMR forwarding form with the date of medical at the required medical center.
The NOC process usually takes around a week. It's better to collect the NOC personally from the DGCA office located at Safdarjung. Also make sure that they've forwarded your PMR to the medical center as they don't give it to you by hand now a days.
The address for the DMS is:
The DMS (Civil Aviation)
DGCA Technical Wing
Opp Safdarjung Apt.
New Delhi
Niks