Calcutta University don't offers any Bachelors course at its university campus but this courses are offered by the affiliated colleges of the university.

As a result, if any college is asking for the best of 4 score, then they will specify which subjects must be present mandatorily in your best of 4 score. For example, for the course of BSc Physics, the marks of Physics and Mathematics are compulsorily mentioned to be added. So you have to read the application brochure well.

For more information regarding the Calcutta University consider the link below:

https://www.careers360.com/university/university-of-calcutta-kolkata

I hope this helps. Wish you a great eve!