Hello,

After graduation you can't do any diploma course generally in India. Only PGDM course which is post graduate diploma management is offered after graduation course. If you want to do any another related course after your graduation it will be certified course but not diploma. Like any computer basis course or any digital marketing course.

And certificate course is helpful in your job also because you have extra knowledge apart from your general course and it will be eye catching for your office or job sector.

All the best.