I understand that you are really interested in the sport and would want to take it up passionately. But what your parents are trying to probably say is also right when they are disagreeing with you.
Cricket or any sport for that matter is a very short lived career. And not to forget that it really take a lot of efforts to establish oneself in it.
So in order to play safe its advisable that you complete your studies and pursue a professional course while you keep your cricket practice on.
If you are able to sustain your interest while studying take up cricket.
Hope this helps you making a decision.
Also log on to http://www.youngbuzz.com/careers/career-options for more information on careers.
Kindly revert for further queries.