IIM Ahmedabad - Indian Institute of Management Vastrapur Answered Questions

Yes, you can apply for CAT 2017 while working in a bank. Coming to points for work experience, individual IIM's have their rating criteria to rate quality and quantity of your work experience. As a thumb rule, people with work experience between 2-3 year get the highest points and points awarded anything more or less than that reduces linearly. A work experience of 6 months or so will not have any significant effect on your composite score but might sway the interview towards work experience rather than academics.

Cut-off marks for 10th, 12th & graduation is around 50% for admission into IIM A. Having said that, clearing the cut-off score doesn't guarantee an interview call from IIM A. Refer the selection criteria of IIM A to get more clarity in the matter:
https://web.iima.ac.in/programmes/admission-details/admission-procedure-for-pgp-2017-19-batch.html

Admission to IIMs is via a common entrance examination called CAT. After clearing the entrance examination, based on your score, past academics and relevant work experience IIMs shortlist students for written ability test & PI where they will gauge your interest for pursuing MBA. After clearing the same, one gets admission to any of the IIMs.

There is no hard and fast rule and usually depends on the overall performance of applicant and selection criteria of IIM A of that admission year. As a rule of thumb, 90%+ in 10th/12th and 85% in graduation (read engineering) would require upwards of 99.6 percentile in CAT. The lower the academics, the more the CAT score to compensate. Academic diversity do allow some slack in CAT percentile.

I think you need to clear the interview stage cut-off for IIM A to get a call and do well in the interview to convert the interview call. It is not a question of how you completed your degree, but how your composite score (as calculated by IIM A; the process is given on the website) compares with others and whether it makes the cut or not. In the interview, it is likely that this question regarding the completion of your degree would come up, but it is a matter of how well you handle the situation that determines your chances.

Since you have completed a 3-year degree in 5 years, I am assuming you have not-that-great academics. If that's the case then getting admission to IIM-A will be difficult even after getting a high percentile as IIM-A gives substantial weightage to academics.