I have not apply for any college till now I want to do bcom please tell me what to do
If you to do B.com or B.com hons from University of Delhi you should apply for it online now on it's official site as the applications are out, the last date for online registration is 7th June, 2018 for this session. You shall apply for it if you want, you'll get a college on the basis of your 12th percentage and the cutoffs respectively. Following is the link for online registration :-
http://www.du.ac.in/du/index.php?page=ug-admission
Hope this might help you.
There are various colleges and universities which offer B.Com so it would be good if you could tell which specific one you are interested in like DU application window will be open from today so if you are interested then you can go ahead for the same.
For reference, you can go through the below link -
https://university.careers360.com/articles/du-application-form
Good Luck!!!