Commerce

You should not pursue MBA if you want to make your career in the accounting field.
For commerce jobs, finance is a good option. You can work as a financial analyst. You can also pursue MBA in sales and marketing or MBA in HR.

Financial analyst jobs are good options for commerce graduates. Other jobs like merchant banking and credit rating are also good. Accounting jobs can be obtained by pursuing ACCA, CIMA or CPA.

MBA in IB is a very promising career option. If you pursue it from a reputed college, chances are there that you will get a good job. Salary is good. It is not necessary that you get a job abroad. You may have to sit in India and handle various international aspects of the business. There is a great scope of foreign tours.

Yes, you can go for psychology even after being a commerce student as this is a study of human behavior, thoughts and modalities which don't require a person to have a special booking knowledge prior to graduation. Practice matters the most here.

To get admission in B.Sc (IT), you need to study PCM in class 12th with 50% marks. There are few universities, which conduct entrance exams as well.

Any education is for a vocation. So, always keep a job in mind to develop such skills which assist you in getting a decent job. Qualifications are not just for a fancy.

Yes, basically CAT tests matriculation level mathematics with just a few exceptions. Hence a strong grip until matriculation maths will help you crack CAT mathematics comfortably. Just practice will be critical.

Commerce background students can opt for M.Com course. You can also consider courses in hospitality, tourism, etc. You can pursue CA and CS.