As you want to get UPSC Preliminary and Main Exam Syllabus with subjects for doing preparation of exam so here I am giving you same:

UPSC Preliminary Syllabus
Syllabus of Paper I -(200 marks) Duration : Two hours

Current 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 - that do not require subject specialization
General Science

Syllabus for Paper II-(200 marks) Duration: Two hours

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 (last item in the Syllabus of Paper-II) will be tested through passages from English language only without providing Hindi translation thereof in the question paper.
The questions will be of multiple choices, objective type.

UPSC Subjects List:
Agriculture
Animal Husbandry & Veterinary Science
Anthropology
Botany
Chemistry
Civil Engineering
Commerce and Accountancy
Economics
Electrical Engineering
Geography
Geology
History
Law
Management
Mathematics
Mechanical Engineering
Medical Science
Philosophy
Physics
Political Science and International Relations
Psychology
Public Administration
Sociology
Statistics
Zoology

Which subject syllabus you want to get please tell me than I will provide you.