Officially, Hotstar claims 100% of episodes have English subtitles. In reality, ~85% do. The first 300 episodes are perfectly subbed; later episodes have missing lines or incorrect timing.
Watching Mahadev with subtitles is highly recommended even for those with a basic understanding of Hindi. The show uses "Shuddh" (pure) Hindi and Sanskrit terms that carry deep spiritual meanings. Subtitles help in: devon ke dev mahadev all episodes with subtitles link