i am thinking of dropping a year and studying for cat 2019, i graduated in 2018 (btech) and don't have work experience, my question is would dropping affect my chances of getting into a good B school.i would be obliged if you could give me some guidance regarding this matter.

I would recommend not dropping an year. Try to find a job which will help you get more exposure as well as improves your profile's aggregate score with work experience. Try to find a start up or an NGO which will give you ample time to prepare for CAT as well. All the best.