Can I cover the fact that I am repeating class twelfth in my personal statement to strengthen my application in UK/Singapore in USA?

Yes, you can mention repeating Class 12 in your personal statement, and it can strengthen your application if addressed thoughtfully.

Focus on how you overcame challenges, what you learned, and how the experience made you more determined and resilient. Admissions committees in the UK, Singapore, and the USA value personal growth and commitment. Emphasize your progress and readiness for future studies, rather than dwelling on the setback.