Hello,
If you are willing to pursue commerce then you must pursue commerce in 12th rather than pursuing Science or Humanities. There is not other course in 12th related to commerce. In 11th and 12th commerce is itself a particular course. Yes, in graduation you can choose either B.Com (Bachelor's of Commerce) or B.Com Hons.
Good Luck.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile