First of all congratulations for scoring good grades in your 10th. As you say, that you are interested in computers and if it comes naturally to you, then you can check out one of the several options you have.
I will give example of Surat, you can check for your respective state or university.
You must secure similarly good grades in your 12th board exam. That will give you a leading edge in merit counselling and admissions. If there is any entrance exam conducted for a particular University or state to get admission into MSc IT or BCA then you must prepare accordingly.
You will however not be able to apply for engineering seats.
In Surat, you can apply for MSc IT, which has around 30-40 percent intake for commerce students and based on merit list of board results. You can also apply for BCA through central counselling which is also based on board merit. There is no separate entrance exam as of now, but that might not be the case for other universities.