Hello,

As far as civil service exam is concerned, candidates just need to pass Bachelor's degree in any discipline from a recognized university having attained 21 years age,you can apply even in the final year.

UPSC is more humanities oriented, so people from arts backgrounds are already acquainted with the syllabus,which perhaps is not the same case with science or commerce students. But,having said this time and again people from engineering, medical,law and other background people have cracked this exam.

With the subjects that you've mentioned,let me tell you in the past people with Economics (Hons) and even Mathematics(Hons) have qualified this exam. So,think with clarity about your interest and you can have a back up plan too, in case there's something else that interests you apart from UPSC, so you can work and have some years experience in the field,and then appear for UPSC.