The search for "Indian Polity by Laxmikant PDF" is a rite of passage for every aspirant. However, treat the PDF as a —use it on your phone for quick revision during commutes, but rely on the physical book for deep study.
These chapters are non-negotiable and form 60% of the Polity questions in UPSC: Indian Polity By Laxmikant PDF
Some references for further reading on Indian polity include: The search for "Indian Polity by Laxmikant PDF"