The eligibility criterion to appear for the UPSC Civil Services Examination mandates candidates to hold a graduate degree from a recognized university. Applicants must be between the ages of 21 and 32 years, as of the prescribed date, while some categories are granted age relaxations. Candidates must also be Indian citizens, or citizens of certain other countries, according to government regulations. Familiarity with these criteria is essential for aspirants to ensure their admissibility for the exam they seek to undertake.