All CR1/IR1 visa applications go through CDJ consulate. It does not matter where you live.
You can request a medical exam at one of three approved clinics in Mexico. You should do this only after you have received the interview date.
The consulate will let the NVC know when they are ready for your interview and the NVC will give you a date and time via email.
Follow the steps below once you receive an interview date:
https://travel.state.gov/content/travel/en/us-visas/Supplements/Supplements_by_Post/CDJ-Ciudad-Juarez.html#medical_exam_instructions