I should also think about other formats. If there are audiobooks, where can they be found? But the user specifically asked for PDF downloads. Maybe some authors or publishers have PDF versions available through their websites, or for distribution under Creative Commons licenses. Need to mention checking the authors' official websites or publishers' sites.
Make sure to emphasize respecting intellectual property rights and supporting authors. The goal is to guide users responsibly while providing the information they need if the books are legally available.
Additionally, mention steps to legally acquire the books. For example, online retailers like Amazon India, or local bookstores in Karnataka. Also, public libraries like the Karnataka State Open University might have collections that can be borrowed.