No, you cannot enroll in CFA Level 1 immediately after completing class 12. The CFA Institute requires you to meet one of the following at the time of registration, which is either hold a bachelor's degree or an equivalent degree, be an undergraduate student with 23 months or fewer remaining until your graduation month, or have 4000 hours of relevant professional experience. You must first enroll in an undergraduate course, and then you can register for Level 1 in your final two years of that program