Hi,
Do you know if this is an automated email based on someone within McKinsey referring you for a particular position? If that is the case, it's possible you get such emails (incl. reminders) without details to a particular office/ recruiter. The application platform is centralized across offices and regions.
But if in doubt, it's good to reach out to the general email address that should be mentioned somewhere in the email. Or to reach out to the recruiters of the particular office you are interested in.
Hope that helps.
Best,
Marilyn