Giving too many mocks
Most of the students don’t have a grasp over the concepts that are going to come in the exam there are so many complex concepts that require lots of practice and you must not have done enough practice to do the questions in the examination even if you start writing mock without good preparation you will end up scoring low than your peers who have good preparation in all the four papers. First, you need to prepare the subject well before jumping onto the papers. You must be thorough in the subject. Giving too many mocks will depress and demotivate you. Mocks are for optimizing your preparation. Know your preparation level and work on that.
Overconfidence
You must know where you stand and how prepared you are for the examination. Mark out the concepts that you have to revise many times and the concepts which you have understood. I am telling you this because all these subject matters have a large syllabus and you need to be thorough in them.
Preparation Level
You are not writing a university-level paper. You are competing against 2.2lakh students to get a seat.Make your basics and concepts stronger if you have a very average preparation level then you will not succeed even if you have done some hard work and this applies to all the entrance exams UPSC, CAT, SSC and NEET. Do as much practice as you can. When you realize your preparation level is good then go after taking mocks.
Focus on Your Weak Areas
You must be fast at calculations. Mark the areas where you are not getting the questions right and redo that chapter again. Make a copy where you note down all the concepts where you are stuck while taking mock test practice as you can.