Concept:
The term ‘Hermit Kingdom' is used for a place which remained isolated, remote, and culturally distinct for a long period.
Ladakh is often called the Hermit Kingdom because of its remote location, difficult terrain, and strong Buddhist cultural traditions.
Step 1: Understand the phrase Hermit Kingdom.
A hermit is a person who lives away from society.
Similarly, a remote region that remained isolated from the rest of the world may be called a Hermit Kingdom.
Step 2: Relate the phrase with Indian region.
Ladakh is situated in the Himalayan region.
It has snow-covered mountains, monasteries, Buddhist culture, and a geographically isolated location.
Because of these features, Ladakh is popularly called the Hermit Kingdom.
Step 3: Final conclusion.
Therefore, the correct answer is:
\[
\boxed{\text{Ladakh}}
\]