Is Nitin Singhania’s book essential for Indian Art and Culture for UPSC?

Nitin Singhania’s Indian Art and Culture is the most comprehensive resource for the UPSC syllabus, but whether it is "essential" depends on your preparation strategy.
For the Prelims, it is incredibly useful because it consolidates scattered information on architecture, paintings, and music into structured, point-wise facts and comparison tables.
For the Mains, it provides the descriptive detail and vocabulary needed for high-quality answers.
However, the book is quite voluminous. Most toppers suggest starting with the Class 11 NCERT: An Introduction to Indian Art, which offers a concise and high-quality conceptual foundation. If you master this NCERT and supplement it with current affairs, you may only need Singhania as a selective reference for high-yield topics like Temple Architecture or the Bhakti movement.
In short: it is a gold-standard reference but should be read selectively after building a base with NCERTs.