CBSE 12th

Yes, you can apply for KVPY has a specific cutoff that varies every year depending on the paper. However if you score 55-60 in the paper. You are sure to qualify in SA stream. Try to get an intern every summer (maybe a couple of winters). Mail a good professor in your area of interest and state you are a KVPY scholar. You will get a response. Going through those internships will help you expand your horizons immensely (and I cannot stress this enough). Just meeting and talking to professors, research group will help you very much identify your interests and future endeavors. Not to forget the good experience of knowing more people and making friends and contacts. KVPY is a very good opportunity for a select few people.

Commerce is a vast field where you will get to explore a variety of areas based on the course you select like:
Finance
Accounting
Law
Taxation
Auditing
Management
Investing
Insurance
Investment banking
General Banking
Consulting
Supervising
Reporting
Decision making
Teaching
1. Bachelors of Commerce (B.Com):
This is the general degree that spans over a period of 3 years that you can pursue after completing your 12th commerce. Having a normal B.Com degree proves quite handy even if you are pursuing any of the professional courses. It is always beneficial to complete your graduation that may help you later on if you go for higher studies. You can pursue B.Com as a full-time course or through correspondence depending upon your choice. Distance education courses or correspondence courses are beneficial if you are also pursuing a professional course like CA CS etc. Otherwise, a regular degree is a better choice. Key Takeaway:This is the most common and the simplest career choice for commerce students. In fact, even if you think of pursuing any other professional course, having a basic graduate degree proves beneficial in the long term. Bachelors of Commerce (Honours) or B.Com (Hons):
This is similar to B.Com but in an extensive form with specialisation a particular subject or field like Accountancy, management or economics etc. The industry demand for B.Com (Honours) is somewhat better than normal B.Com. However, the admission criteria and eligibility conditions might be similar for both. These may slightly vary for different universities/colleges. Bachelors in Economics:
This is yet another option for commerce students to pursue after their higher secondary education. You will get to experience practical knowledge on various economic concepts, economic policies, analytical methods and programs, etc. If you are keenly interested in economics and want to gain specialisation about the economic framework, this might suit you.
Bachelors of Business Administration (BBA):
This is a 3-year Business administration course helping to build a base in core business disciplines. You get to explore different functional areas of a business environment. So, if you are interested in getting exposure to the various business aspects and get a hold of the concepts of business administration, this course might be your choice.