It seems like you are a fresher to the college and desperately wants to change your branch Biotechnology, which is the most underrated branch of the college, compared to some other branch.
To be precise, a CPI of 8 is considered safe. Try to keep it above 8. But, if luck is on your side, even a CPI of 7.6-7.7 will help you out.
I would like to mention a few points that you should consider before switching your branch and perhaps, these are the reasons that make Biotechnology at MNNIT Allahabad amazing.
The faculty also frequently visits other research laboratories and research institutions in the country and abroad. Additionally, national as well as international conferences were held which were government agencies supported.