Hi, ELIGIBILITY FOR DOING MBA:
The very first requirement to take admission for 2 years full time MBA is that you need to have completed your Graduation with a minimum of 50%, if you belong to General category and 45% if you belong to reserved category.
Once you meet the above criteria you will then have to appear for MBA entrance exams, Personal interview and Group discussion. Based on your final score (Percentile) you may then apply for admission to various MBA colleges accordingly.
Note: You may also apply for MBA entrance exam in case you have only appeared for your final years exam, however need to submit the scorecard later.
But like you said you have scored only 47% then you could apply for entrance exams only if you belong to any RESERVED CATEGORY.
And NO, it is not compulsory to give CET fot MBA, but you cannot get admission in those MBA colleges wherein CET is majorly accepted as main MBA entrance exam. You may still give other entrance exams and get admission in MBA colleges.
Some of the commonly undertaken exams are:CAT for IIM’sCMAT more specifically for MBA colleges in Maharashtra.XAT for Xavier's collegeSNAP for Symbiosis institute PuneNMAT for Narsee Monjee Mumbai
I have just mentioned few MBA Entrance exams apart from CAT, you must first decide your possible choices of college and prepare accordingly.
NOTE: MOST OF THE REPUTED COLLEGES MAJORLY GRANT ADMISSION TO MBA ON CET SCORE.