Several factors influence the selection of candidates for various civil services through UPSC, including merit, general studies performance, and the final interview assessment. UPSC evaluates candidates based on their ability to understand complex issues, analytical capability, and ethical reasoning. Candidates must excel in both written examinations and personal interviews to secure their desired positions. Additionally, the reservation policies and quotas for different categories can affect the selection process. Maintaining a well-rounded preparation strategy that includes current affairs, general knowledge, and interview readiness is crucial for success in this highly competitive landscape.