Just to follow-up, the technicians put down the issue to my TV which is ridiculous since I have a Samsung The Frame, which is a fairly mainstream and costly model. It is even more ridicuous as I an older 4K Fire is much smoother than the abonimation Tata Play is selling.
Their resolution to the issue is that they will fix the compatibility sometime in the future, when the hardware itself is evidently significantly underpowered and till that time I am supposed to just keep paying them for the horrible experience.
In short, don't invest in the Tata Play box if you can because it has got extremely poor hardware, made worse by even worse software. It is topped up by the incompetence of their technical team and customer support.