Hello,

To be eligible for the UPSC exam, you must have graduated from college in any stream and be at least 21 years old in order to apply to become an IPS officer. As someone with a science background who is somewhat biassed, I must warn you to pursue science if you find it appealing. It will serve two goals for you: one, having a science background will help with preparation to some amount, and second, there are many streams and careers you can attempt if you are not able to join the IPS.

Don't interpret this as a recommendation to skip commerce or humanities, though. Since we will require many professionals in the humanities and commerce in the coming years, they each have their unique advantages.

I would advise you to explore your areas of interest. Since you have a very clear and definite aim of getting into the IPS (which, I must add, is fairly uncommon), stream won't matter to you, but since you must study a subject for at least 5 years (+2 and graduation), you must genuinely enjoy it.

Good Luck!!