The significance of Class 12th marks lies in their contribution to the overall educational qualification of candidates for the UPSC Civil Services exam. While there is no direct cut-off based on these marks, having a solid academic foundation often reflects discipline and commitment. Additionally, Class 12th performance can be part of the overall assessment during the interview. Ultimately, while Class 12th marks are not the sole determinant, they can impact one's educational credibility and preparedness for the rigorous UPSC process.