Aspirants can prepare for the unpredictability of the UPSC exam by practicing under timed conditions and simulating the exam environment. Regularly participating in mock tests helps to build familiarity with question formats and time management skills. Additionally, diversifying study materials and engaging with various subjects can broaden their knowledge base, equipping them to handle unexpected questions. Staying adaptable and employing critical thinking strategies during preparation can further enhance readiness for unforeseen challenges.