The formats used in UPSC essays during the Mains exam typically include both descriptive and argumentative styles. Candidates can choose to adopt a narrative format that weaves personal insights or experiences into the essay or a more formal approach, emphasizing facts and structured arguments. Additionally, the essays may require candidates to discuss topics involving critical analysis, social issues, or moral dilemmas. The emphasis is on presenting a coherent and well-organized response within the given word limit, demonstrating clarity of thought and effective communication skills.