Can I get my UPSC answer sheet re-evaluated? What is the official policy?

No re-evaluation on merit is allowed. UPSC only permits a photocopy request (within 30 days of final result) and correction of clerical errors (un-totalled pages, un-evaluated answers). There is no provision to challenge the marks given on content. The Supreme Court in UPSC v. Angesh Kumar (2018) upheld this position.