Regional languages can significantly impact a candidate's performance in UPSC. Proficiency in a regional language can aid in understanding and interpreting questions more effectively, particularly in the preliminary and mains examinations. Candidates who are fluent in their regional languages may find it easier to express their thoughts in the interview, fostering better communication with the panel. Additionally, knowledge of regional languages can enhance comprehension of local issues, making a candidate more relatable and informed in discussions. However, candidates must also ensure they are comfortable with English as it is the medium of instruction in many contexts within the examination.