For a new registration, you'll need to book a reservation online at the website of the registry of motor vehicles, or you can look up the phone number online and call for a reservation, the call center is taking a long time to speak to someone, so online is your best bet.
If you are just renewing online is fast and easy or you need appointment you can get online (appointment) just go on early I did at 3am (went on site to get appointment)
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