B.Com

Gargi College is among top 10 Colleges Of DU. So I suggest Gargi College.

Follow the link:
https://www.shiksha.com/accounting-commerce/articles/top-colleges-of-du-for-bcom-blogId-16963

The UGC NET exam is conducted twice a year for the selection of candidates for assistant professor posts in the university and colleges, to pursue the Ph.D. and for JRF award. The candidates are allowed to apply UGC NET for the subject in which they have completed the post graduation degree or if the subject is not available they can apply for the related subjects. Thanks!

The cutoff marks vary with institutions. If you aim for top colleges Anna university like, WCC, Ethiraj, MCC, DG Vaishnav, Stella Maris, You might probably have 92+ cutoff. In case, you are RC (Roman Catholic) or SC/ST background, the chances of you ending up in Jesuit institution are High even if you have quite less score. Hope you get the College you desire. All the best.

BCom is on yearly basis.
Few colleges have started adding mid term projects also as a final marks.

Economics (Hons. ). The course is designed to provide students with taxation and accounting education along with developing their education skills. The course can be very helpful for those who want to get into the insurance and accounting sector.

No you can't say that it is best but it is good one though.

Every DU College has well experienced and good faculty.
For placement related queries please follow this link:
https://www.shiksha.com/college/bharati-college-university-of-delhi-janakpuri-23938?rf=searchWidget&landing=ilp

Yes you can get with that much percentage but in the later cutoffs.

https://www.shiksha.com/college/hansraj-college-university-of-Delhi-malka-ganj-3062?rf=searchWidget&landing=ilp
On this page you will get to know everything.