Should i drop a year for preparing for the DSJ entrance exam?

Hii Tanmay!
The decision depends completely on you. If you feel like you can definitely crack the exam after taking a drop for an year, go for it. But, you should be absolutely sure about this. If otherwise, wasting one year will not be good. You can even take admission in any bsc course and continue with it , side by side studying for the exam. This will help save your one year. This way, even if you don't crack it, by any chance, the year will not be wasted. Hope this helps.
Good luck!