Degree

You need to be updated. Keep on reading books, novels, newspaper to increase your vocabulary and grammer. Watch t.v. To increase you General knowledge. These are the basic things to be kept in mind while appearing in any comparative exams.
Rest you will get the books related to your exam. Through which you can get the rough idea of the exam and paper format.

BBM or any other Bachelors level degree in business management, business studies, business administration, etc. are non-technical degree. Programme like BE/ B.Tech falls under ambit of technical degree.

It depends completely on your career goal. I hope you mean public service commission. If you mean that and civil services then they are good and rewarding careers. For that you need to work a lot and if you mean any PG degree and not MBA then you may pursue MA in public administration along with it. If you mean MBA in PG then you should prepare well for getting seat in only top 50 B-schools.

Some of the following courses in healthcare, only require two-year degrees. I have tried to list these courses below:
1) Cardiovascular Technician: Associate degree programs are offered at community colleges and vocational schools. Admission requirements vary by school.
2) X-ray Technician: Associate degree in radiology technology
3) Respiratory Therapist courses.
4) Medical Sonography
Regards.

Diploma is good.

Diploma in Engineering is a 3 year course. Graduation in engineering is 4 to 5 years.