Science

BA is the best option. The subjects taught in BA will help you to prepare for banking exam.

Yes, you can become a teacher.

Here is a list of colleges offering micro biology in Surat:
Shree Ramkrishna Institute Of Computer Education and Applied Sciences
Uka Tarsadia University

Why do you want to take lateral entry admission in MCA after M.Sc CS. MCA and M.SC CS are equivalent degrees for higher studies and job.

Both B.Sc IT and B.Sc CS are equally good degrees. Your marks are quite low therefore, you may opt for any degree in which you get admission in a good college. Software Engineering requires lot of hard-work and commitment. You are advised to improve your performance in graduation studies for a meaningful career.