The selection process for the Indian Administrative Service (IAS) through UPSC involves a three-stage examination: Preliminary, Mains, and Interview. The Preliminary exam consists of objective-type questions and acts as a screening test. Candidates who qualify then proceed to the Mains examination, which includes written papers across various subjects and an essay. Those who clear the Mains are called for the personal interview, assessing their personality traits, communication skills, and suitability for a career in public service. Final selection is based on the cumulative scores from all stages.