I think you are asking me this question to prepare yourself a justifying answer at the MBA entrance interview. You need to be convinced of why you want to prefer MBA to MCA? Right? In my mind, MCA is the first step. You complete your technical education first. As far as MBA is concerned, you can even do that once you are in job. To grow technically will lead you to management jobs and at that time you can always join a part-time course. In fact, it makes better sense to do MBA at that time. However, if you get in to MBA with premier institutes such as IIMs, XLRI, FMS then you get in to best companies, who will chalk out your career graph for you to benefit from.

MBA provides thought process, knowledge of tools, teaches methodology of scientific approach and analysis to extract sense out of abstract, to analyze situations of uncertainty to enable the person take rational and better decisions. It emancipates ones' understanding. Thinking. It helps one achieve one's fullest potential. It also gives necessary status to become an elite alumni.

Your counsel.