What's your opinion.

Scored 37percentile in CAT. 18.7(3.25/13.5/4.75) in XAT. Really confused what to do. Should I repeat or apply for existing collages. Currently working in sales at 20k/m salary. I am a 25NEM. 8/8/7. I also have a business idea and I am willing to start it soon but the question that will i regret for not taking MBA may hunt me in future is a ?