Today this is the trend.Everyone after B.tech wants to do MBA.But here is the trick.There are basically two category of people in engineering doing MBA.

Who are already doing job and either want quick promotions or want to have their own business.
Who are not well settled after b.tech and believe that getting MBA will help them in having good job.
But if you want good job after doing MBA then you need to have a degree from good business schools like IIM .Even if you clear CAT, before getting into top IIM you need to face interviews .Also your academic marks will be considered.

conclusion:- IF YOU ARE GOOD IN ACADEMICS AND YOU ARE NOT PLACED THEN MBA IS BEST.INFACT IT IS BETTER THAN M.tech.

Thanks,
Azim