Yes, candidates can choose regional languages as their medium in the UPSC exams. The UPSC permits the use of various languages listed in the Eighth Schedule of the Indian Constitution. This feature allows candidates from different linguistic backgrounds to appear for the exams in a language they are comfortable with. However, it's essential to check the language options for specific papers, as the main examination provides for language preferences but is subject to availability. This policy aims to promote inclusivity and ensure that language barriers do not hinder potential candidates from participating in the civil services examination.