I believe since you do have some time for both your Board Exams and JEE Mains First as well as Second Phase, do take help of online resources and previous years besides completing the NCERT Syllabus and foccusing on Board Exams. Do give JEE Main this year, irrespective of the fact, you plan to drop or not. It will help you to analyse your weaknesses and also getting a strong experience.

Incase you are deeply determined to study in an IIT or NIT, but sincerely know you need better preparation, in this case do drop a year. Work hard, make a strong preparation and test taking strategy for yourself, and I believe you can ace JEE next year with flying colours. However do remember, a drop year might just be the trump card to your success and aspirations, or it might just remain in your resume as a Gap Year. Its your responsibility how you want it to be, and how much sincerely focussed you are for IIT or NIT.

Hey!

crash course is a course where the syllabus of any exam is completed in avery limited period consider it to be two months. And it is almost impossible to cover the entire syllabus and shortcuts to solve the problems in a very limited period if you have not a good understanding of fundamentals. You can try , there is no harm in joining crash course if you clear the exam with crash course then it is well and good otherwise it will give you a basic idea about the preparation , so that you can prepare an effective plan to attemot the exam next year.

thankyou