How much case prep have you done so far? If you are just beginning, I would highly recommend using all resources McKinsey has posted on their website, as those are likely to be the closest in format to what you will encounter on the day. I also generally recommend candidates at initial stages of interview preparation to look over some of the cases/suggestions in classic books like Case In Point or Case Interview Secrets. These are not perfect, but help you get a sense of the format.
Beyond this, it's really a case of getting as much practice as you can with different types of McKinsey-style cases. PrepLounge is a great resource: you can filter for interviewer-led cases, and many of the cases have been written by coaches with a lot of experience conducting interviewers.