Diploma

Without being graduate you cannot be post graduate, so you definitely need Graduation with minimum 50% marks and valid entrance exams score like CAT, CMAT, MAT, GMAT.

Syllabus for all students who appear for JEE Mains is the same. There is no different syllabus for engineering Diploma holders.

Here is the complete details about fee structure and scholarship.
Visit the link : http://www.ipeindia.org/tuition_financial

B.Sc is a graduation degree and MBA in HM is a post-graduation degree.

Yes, you can go ahead with MBA in finance. I would rather recommend you to do it from top 50 B-schools. You can also go for CFA certification after 2 years of experience, which adds more weight on your resume.

Hi Rohan,
There is no short term courses on the basis of Diploma in engineering. You should have graduation with experience, then you can go for executive MBA program.
All the best.