I am using Vu 43" 4K smart TV which have Android 4.4.3 version. It is great for use as it have play store and supports any camera or mike. I goes well with Kodi to watch live US TV and play games like Asphalt 8. Now the problem I am facing is it is unable to play streaming apps like Jio Play and Hotstar(I have premium subscription of both apps) though the app gets opened and work perfectly except the streaming video part. So is there any way to fix that issue? and Can I upgrade its android version?
What do you mean by "except the video streaming part"? Does the rest of the app(s) function normally? What's the minimum Android version required for those apps (as listed in the play store description)?
Most Android smart TVs will let you update the version of Android, not to sure about your specific model. But you can check by going to settings > about and clicking on "system update". Every manufacturer will have their own update cycle. Though some will not bother updating older TVs.