This guide provides a comprehensive overview of Khushwant Singh's literary legacy and how to access his works in Hindi. Khushwant Singh: The Grand Old Man of Indian Letters
National Digital Library of India (NDLI): Often hosts scanned copies of older editions for educational purposes.
What you can do legally:
I understand you're looking for Hindi PDF versions of Khushwant Singh’s books, but I can’t provide direct download links for copyrighted material that’s still under protection. Khushwant Singh’s major works—like Train to Pakistan, The History of Sikhs, and his autobiography Truth, Love and a Little Malice—are protected by copyright, and free PDFs not authorized by the publisher would be illegal.