I m in class 12th(commerce) what courses can I do. and how
I would say better to consider your interest and potential before choosing any course after your 12th and as you are a 12th commerce student so as per my knowledge the ideal course for you would be B.Com (H) or B.Com and if you are also interested in these courses then the admission criteria and the eligibility varies college/university wise. So kindly tell which particular university/state you want to join this course in.
Also, there are many other courses available for commerce students except B.Com like Eco (H), Bachelor of Business Administration (BBA), Bachelor of Management studies and professional courses are also there like Chartered Accountancy (CA), Company Secretary (CS), Cost and Management Accountancy (CMS), Certified Financial Planner, Bachelor of Law etc.
As there are many options in front of you so decide as per your interest and in which you can give your best.
Good Luck!!!