No official Extended Cut Hindi dub exists. Some fans have manually stretched the theatrical Hindi track, but voices pitch-shift and action sync fails.
This article dives deep into everything you need to know about the Hindi audio track for The Desolation of Smaug —where to find it, the quality of the dubbing, the cast, and how to legally access it. The Hobbit The Desolation Of Smaug Hindi Audio Track -
The iTunes store in India offers the trilogy with a Hindi audio option. This is the best option if you have an Apple 4K TV, as the audio is uncompressed. No official Extended Cut Hindi dub exists