Hey,

It's not necessary for you to be a  PCB student to pursue bsc in chemistry. You may also do it if you're a PCM student. Hence the requirement for pursuing bsc hons has changed a bit this year. Now you need to score atleast 60% in maths to get bsc hons in du. Also you need to include english as one of your best 4 four subject with a mandatory of 50% in it.

You need to include english, chemistry and any other 2 core subjects you scored highest as mentioned in the list A.

Hope this helps.