CBSE

Please click on the link to get a list of good B.Sc with physics Honors colleges in India.
https://www.shiksha.com/science/colleges/b-sc-colleges-india?uaf[]=sub_spec&ts=8037856&rf=filters&bc[]=26&ss[]=sp_405&ed[]=et_20

Hi,
Here is a list of the best colleges for the same:
https://www.shiksha.com/mass-communication-media/journalism/colleges/colleges-india
Their eligibility criteria may vary which you can check by clicking on the link of various institutes provided in the link mentioned above.

There is no competitive exam and the admission is based on merit of 12th.

You are already heavily loaded because of Physics, Chemistry, Maths and Biology. Why do you want to take additional load by taking computer science? You are eligible for seeking admission in B.Tech CSE or IT even without computer science as an additional subject in 10+2, but if you are confident of taking load please go ahead with CS as an additional subject.

As you are in last month of admission session for B.Tech so there is approximately no entrance exam left all are over almost. so your 12th score is good so you try in counseling of college through your 12th marks.