Economics

I will give you my views based on the assumption that DU is the only option for you.
B.Com (h) opens up accounting avenues. You can pursue CA along with it but then you will have to do a correspondence course as the new rule of DU does not allow regular B.Com (h) students to pursue CA too.
You must have heard about the Big4: KPMG, Delloit, E&Y, PwC. If you dream of working in these audit companies then this is the apt choice.
My personal advice would be to opt for a regular course if you are getting good colleges like SRCC,LSR or so. Believe me the experience you get there is unmatched and you will cherish it forever.
Economics (hons) does not have accounts in its syllabus. You will get to read subjects like Macro eco, Micro eco, International eco, Stats, Maths, History of Indian eco, environmental eco etc. If you want to do research based work or policy making and/or wish to become a college professor then this is the right choice. Masters in economics is the most preferred choice after this course which is also mandatory for becoming a professor or getting into Indian Economic Services (IES).
There are three other courses that you have not mentioned but I think they might interest you. BBE, BBS, and BFIA. DU conducts an entrance exam for admission to these courses. The final merit list is drawn on the basis of Boards exam marks, entrance test score (BBE) + GD-PI score (BBS, BFIA).