Hii,

During the counselling process , You should not have a backlog. The officials will check your Academic scores and all. There will be no problem if you clear that backlog before the Counselling process. You won't be given admission to Study MBA if you have a Backlog.

It won't create any problems if you have the minimum of 50% excluding the backlog subject in your graduation. Whether you'll get a call from any college depends on your CAT percentile and your past academic records. 

Even if you get a percentile above 95 it will be difficult for you to get a call from the top notch colleges but you can get a call from other colleges. So just try to score more in CAT so that you bag a decent college. 

Good luck