Dropping a year its totally depends on you.

Can you please mention your marks?

If you are taking a drop you should try to get top colleges in WBJEE and you should target other exams as well like JEE Main, BITSAT, VITEEE , SRM and Manipal. So, that you have many options and your year is not wasted. There are many private colleges who consider JEE main score to take admission including your WBJEE colleges.

You should be determined and self motivated to crack your exam as if you will not score good marks then after a year also you will be in same track. Work smartly to acheive your goal.

All the Best!!