Hello Aspirant,

I am enlisting down some books which would be very helpful to you for your IAS preparation :-

@History

• India's Struggle for Independence by Bipin Chandra
• NCERT Textbook of Class 11th and 12th

@Geography

• Certificate Physical Geography by GC Leong
• NCERT Textbook of Class 11th and 12th
• World Atlas

@Indian Polity

• India Polity by M. Lakshmikanth
• NCERT textbook of Class 11th and 12th

@Economy

• Indian Economy by Ramesh Singh
• Economic Development Policies in India by Jain and Hari
• NCERT textbook of Class 11th

@International Relations

• NCERT textbook of Class 12th
• Current affairs

@CSAT

• Tata McGraw Hill CSAT Manual
• CSAT II by Arihant Publication
• Verbal and Non-verbal reasoning by RS Agarwal

I hop this information helps you.

Good Luck!!