Hi Suchita. You can do PhD only after acquiring your post graduation degree. And you can choose any out of the two courses- bba and b.com as an initial stage of doing PhD.

And types of bba i.e. BBA streams are as follows:

Human Resource Management

Marketing Management

Accounting and Finance

International Business

Environmental Management

Entrepreneurship development and Management

Retail Supply Chain Management

Rural Marketing Management

Others

Hope this information has helped you:)