B.com is of 2 years I guess... so you have 14 years of education and you can apply.
Go to the link I mentioned and go through online registration. Just remember the username and password as you will need it later. Get a print of the registration form and pay the challan. Finally, post the documents to the address mentioned in the advertisement. After a few days you will receive the admit card for the test. When the results are published on the site you will require the password and login email you gave earlier. If selected, you will be called for an interview.