All India Combined Competitive Examination for the Civil Services conducted by the Union Public Service Commission (UPSC) comprises of two successive stages:
* Preliminary Examination : It is of objective type, which is a qualifying examination.
* Main Examination : It consists of written examination and interview.
The Preliminary Examination is held in May/June and the Main Examination in October/November. One must begin preparations of the main exam along with preliminary exam. This is because there is little time for the Main exam if one waits for the results of the Preliminaries.
A candidate is permitted 4 attempts at the examination. If a person appears in the Preliminary Exam or even appears in one paper, it is counted as an attempt.
Selection to the Indian Forest Service, on the other hand, is on the basis of a written test held in the month of July/August every year. The test comprises: two compulsory papers (General English and General Knowledge); and additional papers in any two subjects chosen from the following options: agriculture / botany / chemistry / physics / geology / zoology / mathematics / agricultural engineering / chemical engineering / civil engineering / mechanical engineering , excepting combinations of agriculture and agricultural engineering , chemistry and chemical engineering.
Preliminary Examination The preliminary examination consists of two papers:
* Paper I — General Studies 150 marks
* Paper II — An Optional subject 300 marks
Subjects for Paper II (one subject to be selected): Agriculture, Animal Husbandry and Veterinary Science, Botany, Chemistry, Civil Engineering, Commerce, Economics, Electrical Engineering, Geography, Geology, Indian History, Law, Mathematics, Mechanical Engineering, Medical Science, Philosophy, Physics, Political Science, Psychology, Public Administration, Sociology, Statistics, Zoology.
Both the papers will be of objective type questions (multiple choice). The question papers are set in Hindi as well as in English. The course content for the optional subjects will be of the degree level. Each paper is of two hours duration. Blind candidates are allowed an extra time of 20 minutes for each paper.
Main Examination It Consists of the following papers:
* Paper I – One Indian language (selected by the candidate) 300 marks
* Paper II – English 300 marks
* Paper III – Essay 200 marks
* Paper IV&V – General Studies 300 marks each
* Paper VI-IX – Any two subjects (optional papers to be selected by the candidate) with two papers each 300 marks for each.
Each paper is of 3 hours duration.
Optional Papers: Agriculture, Animal Husbandry and Veterinary Science, Botany, Chemistry, Civil Engineering, Commerce, Economics, Electrical Engineering, Geography, Geology, Indian History, Law, Mathematics, Mechanical Engineering, Medical Science, Philosophy, Physics, Political Science, Psychology, Public Administration, Sociology, Statistics, Zoology. The following combinations not allowed are:
* Political Science & International Relations and Public Administration
* Commerce and Management
* Anthropology and Sociology
* Maths and Statistics
* Agriculture and Animal Husbandry and Veterinary Science
* Management and Public Administration
* Animal Husbandry & Veterinary Science and Medical Science
* Any two branches of engineering.
The final stage of selection is the interview which is conducted in April/May every year. Candidate will be asked questions on matters of general interest. The object is to assess the personal suitability and judge the mental caliber of the candidate. The candidate must exhibit an intelligent interest in events happening around him so that he appears to be a complete personality.
There is also a medical test, especially rigid for IPS. Out of the final candidates selected top rankers are appointed as IAS officers.
Once appointed, all probationary officers of the All India and Central Services undergo a compulsory foundation training.