Can I update my iPhone 6 to iOS 16.2

No only goes up to iOS 15 for the 6s and 7/7 plus for iPhone 6 it only goes up to iOS 12 the only phone that runs iOS 16 is the iPhone 8

Neither the iPhone 6 nor iPhone 7 is capable of 16 or above.

(257616)

Probably you are looking for higher iOS version for downloading a few apps that require higher iOS version. This may help you --> Apps that require higher iOS versions than your device can be updated to... - Apple Community

the only phone that runs iOS 16 is the iPhone 8

And.....the iPhone X.