According to the official notification of Union Public Service Commission there are 24 subjects of optional subjects from which a candidate has to choose one subject. Currently subjects of literature and language are not allowed in the preliminary examinations. The list is following:
| Agriculture Animal Husbandry & 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 |