Here I am giving you syllabus for Indian administrative service preliminary examination of union public service commission below :

IAS Prelims Syllabus
IAS prelims have following two parts, each part consist of 200 marks
General Studies Paper I: 100 questions
General Studies Paper II: 80 questions

CSAT General Studies Paper 1 Syllabus
Current Affairs: Events of national and international importance
History of India and Indian National Movement
Indian and World Geography - Physical, Social, Economic geography of India and the World.
Indian Polity and Governance – Constitution, Political System, Panchayati Raj, Public Policy, Rights Issues, etc.
Economic and Social Development – Sustainable Development, Poverty, Inclusion, Demographics, Social Sector Initiatives, etc.
General issues on Environmental Ecology, Bio-diversity and Climate Change (no subject specialization required)
General Science

CSAT General Ability Test Paper 2 Syllabus
Comprehension
Interpersonal skills including communication skills
Logical reasoning and analytical ability
Decision making and problem solving
General mental ability
Basic numeracy (numbers and their relations, orders of magnitude etc.) (Class X level), Data Interpretation (charts, graphs, tables, data sufficiency etc. - Class X level)
English Language Comprehension skills (Class X level).
Questions relating to English Language Comprehension skills of Class X level. (will be tested through passages from English language only without providing Hindi translation)