Hey,

First of all, let me tell you the importance of each of this field individually

Bcom

This is the subject of hard core accounting. You will be well versed with the accounting concepts and get an overview of economics and business through this course. The syllabus is an age old course and is quite theoretical.

Bba

This is a fairly new course compared to Bcom. This is more like a mini mba. It gives you an overview to the management concepts. It is an interactive course that will help you improve your communication skills and soft skills. It has a lot of projects and research work to be done.

Bca

This is a coursework for the students with a technical flair. It is about computer languages, web designing, computer programming etc. If you have technical interest then you can join this course. It is not theoretical and completely different from BBA and Bcom.

You have to decide what you can do and take up the course according to your abilities. Do whichever course you want but try to do so from a reputed institution. The course structure will vary according to the type of college. Also, a better brand of college will remain with you for the rest of your life.