Many of these are available on archive.org.
Chief editors: R C Majumdar and S Ramakrishnan
History and Culture of the Indian People, Volume 01, The Vedic Age archive.org link
History and Culture of the Indian People, Volume 02,The Age Of Imperial Unity archive.org link
History and Culture of the Indian People, Volume 03, The Classical Age archive.org link
History and Culture of the Indian People, Volume 04, The Age Of Imperial Kanauj archive.org link
History and Culture of the Indian People, Volume 05, The Struggle For Empire archive.org link
History and Culture of the Indian People, Volume 06,The Delhi Sultanate archive.org link
History and Culture of the Indian People, Volume 07, The Mughul Empire archive.org link
History and Culture of the Indian People, Volume 08, The Maratha Supremacy archive.org link
History and Culture of the Indian People, Volume 10, British Paramountcy And Indian Renaissance, Part 2 archive.org link
History and Culture of the Indian People, Volume 11, Struggle for Freedom, Part 1 archive.org link
Published by Oxford University Press
A History of South India by K A Nilakanta Sastri archive.org link
The cōḷas by K A Nilakanta Sastri archive.org link
The Pandyan kingdom by K A Nilakanta Sastri archive.org link
The Wonder That Was India archive.org link
Ancient Indian education archive.org link
Local Government in Ancient India archive.org link
State and government in Ancient India archive.org link
Corporate life in Ancient India archive.org link
Education in Ancient India archive.org link
The above page was a result of a twitter discussion on May 25, 2020, the person asking for recommendation finally settled on these books: