B.Sc

1)The first and the foremost, you need to fill an online application for Delhi University mentioning all the courses that you wish to seek admission in. Though, you can also go for offline application but it will be convenient to fill it online. You will also be required to fill your class 12th board marks subject wise.
2) Next, wait for the cut off lists.
3) For B.Sc courses, the cut-off is to be calculated as for physics, chemistry, zoology, botany, etc. and your cut-off is calculated as per your percentage in PCM.
For mathematical sciences, computer science, mathematics and statistics, cut-off is calculated as the aggregate of marks in mathematics, one language subject and two best elective subjects.
For B.Sc pass courses, again your aggregate of your marks in PCM will determine the cut-off.
There are yet another courses, which follow different procedures. To know about them, you can visit the official website of DU.
4) DU releases its cutoff list. It will be available on the DU's website and on the associated colleges' websites. Also, in some of the leading newspapers. Look up for your course. Check, in which college's cut-off you fall. If you wish to take admission, make your move.
5) Rush up to the college. Get your documents checked. Do not forget your DU application. And make sure that the course in which you are seeking admission is mentioned in your application. Fill in the required forms, attach necessary documents, and deposit your fees. You have made it to DU.
6) If by chance, you could not make it to the college of your choice in the first list. You can wait for the subsequent lists. And follow the steps 4 and 5.
For better knowledge, check the official DU website. Check it regularly for more updates. Also download this year's admission prospectus (once available) to understand DU more clearly. If you live near Delhi, you can also visit the Open Days Session of DU for better knowledge on admission process. The details of these will also be available on DU's official website.

Here are few good colleges for B.Sc:
1.IIFA Multimedia | Top B.Sc & Diploma Interior Designing Animation
261, 9th Main Rd, Srinivasnagar, Banashankari, Bengaluru, Karnataka 560085
2.Dr. B. Lal Institute of Biotechnology
6-E, Malviya Industrial Area, Jaipur, Rajasthan 302017
3.Loyola College
Sterling Road, Near Nungambakkam Railway Station, Nungambakkam, Chennai, Tamil Nadu 600034
4.BFIT Group of Institutions
Chakarata Rd, Sudhowala, Uttarakhand 248007
5.St. Xavier's CollegeMahapalika Marg, Dhobi Talao, Chhatrapati Shivaji Terminus Area, Fort, Mumbai, Maharashtra 400001
6.Indian Institute of Science
CV Raman Rd, Devasandra Layout, Bengaluru, Karnataka 56001
7.Sikkim Manipal University - Distance Education Learning Centre
5th Mile, Tadong, Gangtok, Sikkim 737102

Here are few good colleges in Chennai for B.Sc in physics:
1.Loyola College
Sterling Road, Near Nungambakkam Railway Station, Nungambakkam, Chennai, Tamil Nadu 600034
2.Madras Christian College
Tambaram, Chennai, Tamil Nadu 600045
3.Meenakshi College for Women
No.363, Arcot Road, Kodambakkam, Chennai, Tamil Nadu 600024
4.Anna Adarsh College for Women, Chennai
A-1, II Street, Off 9th Main Road, Anna Nagar, Chennai, Tamil Nadu 600040
5.Women's Christian College
College Road, Opp Standard Chartered Bank, Nungambakkam, Chennai, Tamil Nadu 600006
6.Dwaraka Doss Goverdhan Doss Vaishnav College
833, E.V.R. Periyar High Road, Arumbakkam, Chennai, Tamil Nadu 600106
7.Guru nanak college
Velachery road, Chennai, Tamil Nadu 600042