Hello there,
You haven't mentioned your Home State so I'm giving you are list of colleges throughout the country. List of good diploma colleges for computer science are as follows:
1. Maharaja Sayajirao University of Baroda, Vadodara
2. Lovely Professional University, Phagwara
3. Jamia Millia Islamia, New Delhi
4. Dr Vishwanath Karad MIT World Peace University, Pune
5. Techno India University, Kolkata
6. Integral University, Lucknow
7. Nitte Meenakshi Institute of Technology, Bangalore
8. Government Polytechnic, Nashik

For more information about the same you check the link given below:
https://engineering.careers360.com/colleges/list-of-diploma-in-computer-science-engineering-colleges-in-india

Hope this information helps you.
Good luck!!