See you cannot compare CAT mock test with actual exam at all. Mostly the actual exam is lot more tougher but there is no surity some section might get same as mock test some might be difficult. So there is no surity.

To know yourself in a better way you should attempt lots of online mock test from different websites like hitbullseye, oliveboard, Testfunda, youth4work, sample paper of career launcher etc. All these scores will give you better idea about your score and not only that you can also see your predicted percentile. These online mock test will also help you in overcoming your mistakes and come up with a strategy to attempt your paper which will definitely help you in improving your marks and percentile.

Through these tests you can also know about your strength and weakness which will help you in attempting easy questions first that will help you in reducing the chance of errors and missing an easy question and also you will get enough time to attempt medium level questions so this will overall improve your speed and accuracy leading to increase in percentile.

All the best for your preparations and exams!!