Sanjeev generall a year gap is not a problem while going to pursue your MBA degree from any b-school. But that year gap is considered to be good for 1-2 years. 

Generally, students take year gap after 12th class to get admission in a good college to graduate then maybe a year after that for MBA exams preparation. Most of the students don't even do that they either prepare in the final year of their graduation or while working after graduation.First of all your 4 years gap is a big number secondly if you want to do MBA, no-one is going to stop you from appearing in the exams.

But you need to do two things in order to get admission in any college first get a very very high percentile so that you have an upper edge as a comparison to other students. Second, you need to prepare valid answers why you took the year gap for such a long time.

If you are able to justify that your inconsistency in education has some valid reasons and at the time when you took year gap, you actually were working on something which helped you in improving yourself then it will be fine and you will get admission in the college. But if you are not able to do these things then it will be very hard for you because interviewers will judge as you the person who is not confident and does not have the power to tackle difficulties.

All the best!!