Hello,

You just need to be 21 years old having completed graduation in any discipline from a recognized university.You can apply for UPSC even in final year. UPSC doesn't discriminate amidst aspirants belonging to different discipline, people from different backgrounds have cracked this exam and continue to do so, eventually it's the preparation and strategy that matters.

You can also go through UPSC syllabus in order to choose your subject in graduation, if you're inclined towards humanities subject like economics, political science, geography etc, you can pursue the graduation in the same. In this way, you'll also find it easier when it comes to your optional paper in UPSC. But, inspite of the fact that UPSC is humanities oriented, people from different background have cracked this exam, and continue to do so, extra efforts for people beloning to background other than humanities lies in the fact that they've not studied usually humanities subject in their 10+2/graduation level but then that should't anyway discourage, as I said people from different background have succeeded in this exam.