Hi,

The basic meaning of the category rank is to see where you stand (on the basis of your WBJEE score) among the other candidates of your category. There are a number of seats in most of the colleges which are reserved for separate categories. During WBJEE e-counselling you will notice that they only ask for your general merit rank (GMR) that is because for the online college alotment procedure they consider your GMR only.

Now if you belong to a category, and your category rank is very good (i.e. <1000) then they might consider your category rank and check whether there is any other applied candidate from your category who has a better category rank than yours. If not, then you get one of the few reserved seats in that college under your quota.

Otherwise, they will go with your GMR only.

I hope that was helpful.