Eligibility criteria to appear for the UPSC Civil Services Examination include the completion of a recognized undergraduate degree from a university. Candidates must be within the age limit, typically between 21 and 32 years, with age relaxations applicable for certain categories. They must also be citizens of India or meet specific residency requirements. Additionally, candidates can only attempt the exam a limited number of times, varying based on their category. These criteria ensure that applicants possess the requisite educational background and maturity for undertaking administrative roles.