I’ll tell you the most useful advice about this exam:
A lot, and I repeat, a LOT of students on quora will misguide you about the difficulty level of this exam and the preparation level needed to ace it.
They will tell you its easier than jee mains or the same level as of jee mains. Let me tell you: ITS NOT. WBJEE IS TOUGHER THAN JEE MAINS. let that sink in. which means only a superficial jee main level prep will not help you ace this exam.
besides, the level of prep you need for this exam depends on the rank range you are targeting/aiming for.
1–500 rank requires serious JEE ADVANCED level prep. Which means you cant get a rank less than 500 without preparing for jee advanced.
500–1000 rank requires a prep level of something between jee main and advanced.
1000–1700 requires jee main level prep.