Colleges in Bihar

It differ from university to university.
Some university also take admission of commerce students, but if you don't have Maths background in class 12th, it might be little difficult, but if you can catch up that, I think a commerce student can also apply for BCA course.

You can apply online.

There is no entrance exam for getting admission in Post Graduation Diploma in Fashion Designing in Patna Women's College, Patna University. The only eligibility criteria for obtaining a seat in the college is graduation degree in any discipline from a recognized university.

For UG courses, 12th marksheet is required and for masters your UG degree would be required but you'll have to give the entrance.

The total fees for the course is INR 20,000. The fee has been calculated bases year/semester 1 fees provided by the college. The actual fees may vary.
For more information, click below.
https://www.shiksha.com/teaching-education/secondary-sr-secondary-school/course/b-ed-nalanda-open-university-bihar-other-270194

There is no entrance test required for getting admission to Post Graduate Diploma in Journalism and Mass Communication of Nalanda Open University. However, you need to check the eligibility requirement to apply for the course which is to be a graduate in order to pursue the course.