Hi Aspirant,

It all depends on your personal preferences. Graduates in finance or economics are not allowed for foreign service, although mathematics and statistics are allowed. Any graduate is welcome to apply for IAS.   For IAS, many people have a BA in sociology, and for IPS, they have a BA in psychology. In UPSC, geography is the most vibrant and populated subject. Little has been said about physics, chemistry, and biology. Finally, you choose your subject based on your own decision/conscience rather than being influenced by others. You know what you desire and what your capabilities are. Take advise, but don't be influenced by it. If you want some advice, I would recommend Bsc. Geography Hons is superior to physics and computer science. Also geography help you in your 3 years of college which will help you while preparing for UPSC (In prelims, mains GS1&GS3 and mains optional)

Hopee this helps.

Good Luck!