Bachelors

Hi Tharun, most universities require a four years bachelor degree, applicants holding a three year bachelor degree must typically get their degree evaluated by certain third party evaluation agencies like WES etc. That said, admission requirements vary with universities and also depends on an individual's profile including academic grades, GRE scores, work experience and so on. It is best if you check the university department pages and also email your profile to a few universities and hear what they have to say. University of California - Berkeley, Carnegie Mellon University, Purdue University and University of Illinois at Urbana-Champaign are some of the best.
Hope this helped.

From your question, it seems that u hv just cleared your hsc. Stream cannot be guessed from your question. See, when u r choosing a subject in grad level, u hv to keep certain things in your mind likewise your academic domain of hsc, your wish, your interest, your passion, your ambition and aim. Keeping all these in mind, you should choose your grad subject in a good college. Now coming to your first query about mba and mca, this is to say that mba is a subject of business domain and mca is from computer domain. To pursue mca, u need to hv computer and maths in grad level and for mba u can be a graduate of any stream preferably it is for candidates holding degrees in btech, bcom, bsc in applied sciences/ applied biosciences, bjmc. So first of all choose subject in bachelor level then think of masters. Move step by step or u may mesh up. All the best. Thank you.