Hello Aspirant,

Review the Preliminary and Mains exam syllabuses. Examine the previous years' preliminary and main exam question papers. Start routinely reading the newspaper and taking brief notes on items that interest you. After reading the foundational NCERT books, review the pertinent textbooks for the UPSC syllabus.

You can refer the below link:

https://competition.careers360.com/articles/upsc-ias-syllabus

ALL THE BEST