Hi Vishal,

If by entrance classes,you mean coaching classes for entrance exam,then definitely you can go for preparing for the entrance exams along with your 12 class exam.But you will only be allowed to give entrance exam once you have applied in a college after class 12th.

Thus ,you can start to prepare for the entrance exams right now also,but as a suggestion if you are currently giving your 12 Boards,then you must first focus on them,since 12th Boards percentage are really important at any step if your college.But as far as going for entrance exam coaching classes,you can go for them.

Thank You.