Is it right for me to just start preparing MBA with my full spirit and just manage to pass in my B.Tech exams? I am currently in 2nd sem.

If you were so sure about an MBA, why opt for B.Tech in the first place? Now that you gave taken this decision, it better to focus on B.Tech for the time being. The graduate percentage is an important criteria and is considered by all top schools for final selection. Even at a B-School you would be