Hi,

You can find all the previous year UPSC questions on it's official site only. They provide all the question papers along with the answer keys. These papers are given according to the years, you can also search the specific exam you are lookin for.

Here is a link you can refer for the question papers: https://www.upsc.gov.in/examinations/previous-question-papers

Just copy this link in the browser.

I hope this helped you.