Thanks for writing your query at www.careerguide.com!
Well, you have completed MCom, appeared for CS exam but could not clear it and now you are confused about the future.
Your four attempts signify that you want to be CS but at this point of time you seem to be disappointed with failures. At this point of time, doing another course would be risky. Please note that you are in right direction of your career and complete the CS. As suggested by Dr. Anand. I would recommend you to appear for CS exam till you clarify it. Attempts don't matter, matter is your hard work, patience,