During the UPSC interview, a candidate's leadership abilities can be inferred through their responses and behavior. Interviewers look for qualities such as decisiveness, communication skills, and the ability to work collaboratively. How a candidate articulates their vision and approach to problem-solving demonstrates their capability to take charge in challenging situations. Instances from their past experiences where they exhibited initiative or overcame obstacles could showcase their potential as a leader. Additionally, confidence in presenting ideas and adaptability to questions reflect critical leadership traits valued in civil service.