First of all you need to see the eligibility criteria for sitting in the MBA exams or for applying in most of the colleges. Eligibility criteria is to have atleast 50% in 10th 12th and graduation for general category students and 45% for SC/ST students.

As you have less than 50% in 12th then you won't be able to.sit in most of the MBA exams but you can sit in XAT exam where you will need to score a very high percentile to get in some good college.

There are few colleges whose eligibility criteria is only to score above 50% in graduation. So you can be eligible for it but first prepare for XAT exam and get a very high percentile in order to cover te loss due to academic records which is one of the key parameters used by college in order to call students for next round of interview and WSAT. Later you will also need to do very well in interview and WSAT becuase this % is also used as ONE one of the parameter in final merit list.

All the best!!