How to upgrade Android 5.1 to Android wear OS?
Please suggest
Buying an Android Wear OS smartwatch.
you can’t, just like you can’t “upgrade” your Android phone to iOS.
@Stephan_Schwobel - both platform are on Android still not possible… very surprise!
@Rakesh_Pandya both platforms come from Google, but are two separate operating systems. Android Wear OS is the old term and now is called Wear OS by Google.
If it would be possible, I wouldn’t call it upgrade. I would call it downgrade… 
Neither can you switch Android 7.1 to Wear OS 2.0
@Rakesh_Pandya you could buy a Samsung gear s (1st gen). It can handle Tizen OS, Android 5.1 and Android wear.