Hello!

Unlimited here refers to test. That is, you will have unlimited number of attempts in the test series provided by the pacakage you want to purchase. This will help you to improve your speed. It has additional features too such as to analyse your performance in tests so that you can identify the areas in which you are good and weak at and dedicate time according to that and improve. Since it has chapter wise tests too, it would be helpful to cover the entire syllabus.

All the best and prepare well!