Please follow the links i.e. http://www.upsc.gov.in/ for the IAS syllabus.

I don’t know much about IAS Syllabus and Subjects but I have collected some information about this, I hope the information may help you.

The IAS syllabus includes General Studies where you would be attending paper, which include includes topics like:

Paper 1:

- History of Modern India and Indian Culture

- Geography of India

- Constitution of India and Indian Polity

- Current National issues and topics of social relevance

- India and the World

- India’s Economic Interaction with the World

- Developments in the Field of Science & Technology, IT and space

- International Affairs and Institutions

- Statistical analysis, graphs and diagrams

English Paper:

- English Language and Comprehension skills

- Comprehension of given passages

- Logical reasoning and analytical ability

- Short Essay

Indian Language Paper:

- Comprehension of given passages.

- Precise Writing

- Usage and Vocabulary.

- Short Essay

- Translation from English to the Indian language and vice-versa

The marks scored in these papers English and Indian languages will not be counted for ranking. For the Indian Languages papers you have to write it in the respective Indian language excluding the translation part. 

There are also optional subjects which should be attended along with this above mentioned general studies. The optional subjects includes Civil Engineering, Physics, Mathematics, Mechanical Engineering, Medical Science, Psychology, History, Geography, Public Administration, Mechanical Engineering, Law, Mathematics, Chemistry, Geology, Agriculture, Sociology, Zoology, Political Science, Civil Engineering, and Economics.

However, you can select the optional subjects as per your wish but whereas general studies papers are compulsorily need to be attended. Well, if you have any questions regarding the subjects and syllabus of IAS examination, you can revert back to me or else can check-out this link http://www.upsc.gov.in/.