Investment Banking

For being an entrepreneur you have to be an all-rounder in the field of marketing, HR, finance, operations, etc. As you are to establish your own business so you need to be more productive and should have all the domain knowledge which would be required to execute your business idea into reality. You must be able to market your product, able to prepare account; balance sheet and effective manage of your Human resources. So it has been ruled out that BBA finance is over BBA marketing as if there would be no market then how would you be able to create funds and prepare account. So both are crucial but you can choose marketing as it would be including some of the basics of accounts and finance as well before coming to core marketing. So, you need to be full of knowledge of every domain to become entrepreneur.

Let me brief you about Investment banks first. Investment banking is divided into three broad areas, the front office, the middle office, and the back office.
1. The front office comprises the client facing roles like traders, mergers and acquisition analysts, underwriters etc.
2. The middle office consists of research and risk management roles like equity research analysts, risk managers etc.
3. The back office recruits employees for support roles who take up tasks like clearing and settlement processes, bookkeeping etc. Now for you, if you are a graduate in finance B.Com BBA BMS etc. ), then you can do some certification courses and get into the back office roles. You won't be recruited for the middle or front office roles. If you are an engineering graduate, then also you have a chance of getting recruited for back-office roles. You can refer to the following article to understand how to start a career in investment banking:
How can a graduate get into Investment Banking - https://www.learnwithflip.com/blog/for-individuals/how-can-a-graduate-get-into-investment-banking/
If you get an MBA, you'll have an edge over others and can get recruited from campus placements. So to answer your question in simple words, you can do any course, B.Com or BBA.