Hi...

Yes you can apply for the exam even if you have the backlog. Candidates who are appearing for the supplementary re-exams are also eligible to apply for CAT,MAT or ICET exams.

While applying foe CAT exam you have to select the "yes" option for the question " Are you in final year of Bachelor degree?". Since your graduation is not complete you have to take the certificate from your college principal or registrar of the university mentioning that you are appearing for the supplementary exam.

The rule here is that finally when you complete your bachelor degree there must be minimum of 50 percent. For the reserved categories the minimum percentage for the bachelor degree must be 40 percent.

All the best