IAS Examination is also called as Indian Administrative Services Examination, it is conducted by UPSC

Preparation Tips
Solve previous year question papers

Try to take a few mock tests

Make a routine and stick to it.

Read latest GK books

Make short notes of it

Exam Pattern:
IAS examination is conducted in three phases:
Phase 1: Preliminary Examination or CSAT (Objective Section)
Phase 2: Main Examination (Subjective Section)
Phase 3: Interview (Vocal Section)

Phase 1: Preliminary Examination – CSAT Syllabus:
CSAT or Civil Services Aptitude Test is the Preliminary examination of UPSC, it test the aptitude of examinee to tackle Reasoning and Analytical questions. Consist of two papers, each of 200 marks and two hours of duration and it is compulsory to appear in both.

It is an Objective section, and every wrong attempt will cost you 1/3rd marks of the attempted question.

CSAT is just a screening test, thus the marks obtained will not be entertained in your final merit.

Syllabus for Paper 1:
Current events (National and International)
History of India
Geography of the world (Physical, Social, Economic)
Indian Polity and Governance-Constitution
Economic and Social Development
General Issues (Environmental Ecology, Bio-Diversity, Climate change etcs.)
General Science
Syllabus for Paper 2:

Comprehension
Interpersonal Skills
Logical Reasoning and Analytical Ability
Decision making and problem solving
General mental ability
Basic Numeracy
Data Interpretation
Comprehension Skill (English)
Phase 2: Main Examination Syllabus (1750 Marks):
This phase will test your academic and intellectual talent in depth. It consists of 9 papers, in which two are qualifying papers of 300 marks each:

I. Any Indian Language

II. English

These two papers just need to qualify which is mandatory and marks obtained will not be considered or counted.

Language for the rest seven papers can be any of the languages mentioned in Eighth Schedule of the constitution or you can opt for English. Rest seven papers are mentioned below, each weighing 250 marks:

III. Essay

IV. General Studies 1 (Indian Heritage/Culture, World History & Geography)

V. General Studies 2 (Governance, Constitution, Polity, Social Justice and International Relations)

VI. General Studies 3 (Technology, Economic Development, Bio-Diversity, Environment, Security & Disaster Management)

General Studies 4 (Ethics, Integrity & Aptitude)
Optional 1 (Of your choice)

VII. Optional 2 (Of your choice)
These are the optional subjects from which you can choose your preference:

Agriculture
Animal Husbandry and Veterinary Science
Botany
Chemistry
Civil Engineering
Commerce
Economics
Electrical Engineering
Geography
Geology
Indian History
Law
Management
Mathematics
Mechanical Engineering
Medical Science
Philosophy
Physics
Political Science
Psychology
Public Administration
Sociology
Statistics
Zoology
Anthropology
Assamese
Bengali
Chinese
English
French
German
Gujarati
Hindi
Kannada
Kashmiri
Konkani
Malayalam
Manipuri
Marathi
Nepali
Oriya
Punjabi
Russian
Sanskrit
Sindhi
Tamil
Telugu
Urdu