CBSE

Hi,
You can attempt improvement exam of specific papers where you feel needs improvement. Please check with CBSE and your school for details and requirements.

If you wish, you can opt for your choice of course. If you have 60% marks in 12th, then there are slim chances of getting into DU.
So, you have little options left. IP University, Christ University and others who have an entrance examination like Narsee Monjee.
If you go for other private institutions then Amity University, Galgotia University, etc. are available.

Yes, you can but see that it does not affect your boards exams. Colleges have specific entrances, you need to check with the colleges on their websites for specific info.

In B.Com, you are going to have subjects like accounting and economics. You are going to study three types of economics in 3 years. Those are microeconomics, macroeconomics and international economics.

Hello Lekhika,
Yes, you can apply just for one subject in the improvement exam which can be clubbed with your previous marks if you score more than what you have scored previously.

Hello Vijay,
In the present system, I don't think you have an option of appearing for an additional paper in 12th or set of papers again! Also, what will you do? You would have become age barred.
Take up some graduation course.

Yes, you will get a new mark sheet.