Hello aspirant,

The optional subjects of UPSC are:

• Anthropology
• Animal husbandry and veterinary science
• Mechanical engineering
• Mathematics
• Philosophy
• Physics
• Geology
• History
• Law
• Geography
• Electrical engineering
• Economics
• Botany
• Chemistry
• Civil engineering
• Management
• Medical Science
• Political science
• Psychology
• Public administration
• Sociology
• Statistics
• Zoology
• Literature of any one language
• Agriculture

Hope it helps you.