Thanx...I checked my Airtel Xstream stb for update and saw an update for Hotstar. It's 3.5.2 version. Updated it and checked with Togo. The resolution is varying between 4K to 1080p in the stats. Sometime it's 1080p and sometimes it's 4K.
My internet plan speed is 200 Mbps.
Also checked Avengers Endgame. It's showing DRM error.
I think latest update have done something for 4K movies in those Android boxes...Even in 200 Mbps speed too it's not stable as u said...