To be cleared by the NCAA Eligibility Center, you will need to obtain an amateur certification as part of the process. To be eligible to compete in college, the NCAA has to verify that you have not competed at a professional level and have not received any benefits from competing. Individual institutions are responsible to determine the amateur status of their prospective athletes as covered by the rules of the NCAA.
Some of the things that affect your amateur status: contracts with a professional team, salary for participating in athletics, prize money won, play with professionals, tryout/practice/competition with a professional team, benefits from an agent, agreement to be represented by an agent, and the organized-competition rule.
In order to earn your amateur certification from the NCAA, you have to request for the certification through the Eligibility Center. Your information and experience will be studies by a representative, and if there is an issue, an appeal process may take place. Once it is reviewed and confirmed, that part of the eligibility process is cleared.