Non-graduates cannot take the UPSC civil services examination as the eligibility criteria explicitly require candidates to possess a degree from a recognized university. This criterion is in place to ensure that aspirants have a foundational level of education and critical thinking skills necessary for the complexities of civil services. However, graduates from any stream can apply, which highlights the inclusive nature of the examination, allowing for diverse disciplines. Aspiring candidates are encouraged to pursue their degrees before aiming for the UPSC exams, enabling them to acquire the essential knowledge base needed for effective public service.