In situations with limited revision time, aspirants should prioritize subjects in the UPSC exam based on their strengths, weaknesses, and significance in the syllabus. Begin by reviewing high-weightage subjects that yield higher marks and focus on topics with consistent past emphasis. Allocate more time for challenging subjects while ensuring comprehensive touches on familiar ones. Utilizing short notes and summarizing key concepts can aid retention. Mock tests during this time can help identify remaining gaps and enhance time management skills before the exam, ensuring effective preparation.