Hello, Shivam. There are few best colleges in which you will be eligible to take admission for B.com (Honours) Courses.

1. Delhi University: As there are around 90 colleges affiliated with Delhi University, so you will have the changes for getting admission in best government colleges after 3rd or 4th Cut-off.

But you will not be able to get admission in topmost colleges like Sri Ram College of Commerce, Hindu College, Hansraj College, etc as the cut-off merit list is very high and all the seats get occupied at 1st and 2nd cutoff only with least cutoff around 95-96%. So, I would suggest you to register for it and wait for the 3rd/4th Merit List.

2. Banaras Hindu University (BHU): The minimum eligibility criteria for registering at BHU is 50% marks in Class 12. As your score is 80% so you will be eligible to take admission in BHU. But you need to qualify BHU Under-graduate Entrance Test (BHU-UET). 

For details regarding BHU-UET, please visit here: https://university.careers360.com/articles/bhu-uet-eligibility-criteria

3. Guru Gobind Singh Indraprastha University: GGS-IPU takes admission through Under-Graduate Combined Entrance Test known as IPU-CET. A candidate must have scored 55% in main papers Physics, Chemistry, Mathematics (PCM) or Physics, Chemistry, Biology (PCB). Undergraudate Combined Entrance Exam (CET) is conducted separately for each courses and the selection will be done on the basis of ranks achieved in the examination. 

So these were the top government universities where you can easily apply and get a better college. There are many more colleges and universities located in different states and cities which are conducting various Entrance Test and you may enroll to that as well.

As there are very few top government colleges, so you also apply to best ranking private colleges in India like Symbiosis International University (Pune), Indian Institute of Managmenet and Commerce (IIMC, Hyderabad), Christ University (Bangalore), Chandingarh University (Chandigarh), Prestige Institute of Management and Research (PIMR, Indore) and many more. 

All the best!!!