UPSC examination is the one you should answer if you aspire to join the Indian Administrative services. For eligibility, you should hold a valid Graduate's degree from a recognized university and be at least 21 years old as of August 1 of the year of the examination.
It is held in two parts: The preliminary examination, which tests your knowledge of current and world affairs, climate change, India's and the world's geography, ecology, comprehension skills, logical skills, problem solving abilities etc. 33% is needed to pass this stage which consists of two papers.
Next comes the written test and the personality Interview. For the written test, you need to have an excellent knowledge of world and current affairs, Technical developments, geography, social scenarios, ethics, culture, environment and two papers based on any one regional language which you can choose. If selected, you will be called for the Personality Interview which will gauge the mental qualities of the candidate.