Hi Ishu, 

In a CMC interview there is one on one conversation with one or two interviewers and also some group tasks and individual tasks. In the interview people are asked about their ambitions, aim in life, faith and others by which they try to know your way of thinking about life ,how well you will be able to handle difficult situations in your life etc. so in order to pass these tests what you atleast need is confidence, good body language and quick thinking power and also most importantly good conversation skills. You can vide several videos in youtube in order to improve your communication skills. However i will at first suggest you to complete your preparation and do good in your NEET UG 2018 As that is your only ticket to CMC ! 

Hope this helped ! Keep working hard. All the best for your upcoming exams! :)