The process for re-evaluating answers in the UPSC Mains Examination typically involves a formal application for re-evaluation post-results announcement. Candidates can apply if they believe that an error occurred in the evaluation of their answers. The application usually requires a nominal fee and is reviewed by the examination body. However, it's important to note that re-evaluation may not change the marks unless substantial discrepancies are found. Familiarizing oneself with the official guidelines concerning the re-evaluation process is essential for aspirants seeking this option.