I am belongs to the caste bc-b in which category I should apply for jee mains either OBC or general

Dear student,
Yes you can apply as an obc candidate in jee as bc-b falls under obc category. You haven't mentioned your domicile state, when it comes to state reservations then bc-b category candidates have higher percentage of seats reserved as compared to bc-a. But as jee is conducted by central authorities, all these things do not affect the reservations. But make sure that you produce the required certificates like the obc caste certificate and your family's annual income certificate to prove that you belong to obc ncl category.