The eligibility criteria for appearing in the UPSC Civil Services Examination include being a citizen of India, a specific educational qualification, and age limits as defined for various categories. Candidates must be graduates from a recognized university, possessing a degree in any discipline. Additionally, applicants must fulfill certain age-related requirements, accommodating candidates from different backgrounds—general, OBC, SC/ST, and others. Meeting these criteria is essential for registration and participation in the examination process, ensuring that candidates possess the foundational qualifications for civil services.