This subject consists of concepts from the Constitution of India, the various acts and amendments (generally of the central government, and at times from some of the state governments) and the political philosophies and structures of the country. So, the preparation should cover all of these aspects from the sources one reads from.
Books for initial preparation:
Indian Polity by Lakshmikanth
Introduction to the Constitution of India by DD Basu
TMH Synopsis for Polity
Constitution of India (with latest amendments included)
Indian Parliament by Subhash Kashyap (and other books by the same author)
www.pib.nic.in (daily releases from all ministries)
Questions to solve:
TMH Polity Questions
All the previous papers (for polity questions)
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