I want to update my iPhone to the latest version of iOS 14

Hello,

An iPhone 6 (or 6 Plus) will only update as far as iOS 12.5.7. To ensure you have at least that, you can try updating your device. When updating, your device will update to the highest version currently available that it will support, or it will just say it is up to date and won't offer to install anything. If you want to run a higher system version than your current device will support, you need to buy a newer device.

This support article has instructions about updating your iPhone or iPad wirelessly --> Update your iPhone or iPad - Apple Support

You can also use Mac and PC computers to update system software. That is outlined in this article --> Update iOS on iPhone - Apple Support

i want to update my iphone 6plus to the latest version 14 ios

Unfortunately, you can't.

iOS 12.5.7 is the end of the road for the iPhone 6 Plus. No more updates are available.

You can’t

iOS 9 was the end of the update road for the 4s; with it’s last update being nearly 5-years ago.

I what to update my iPhone 6plus to a new version of iOS 17

I want to update my iphone 4s to iOS 13.4

iPhone 4s isn’t compatible with iOS 10 and latest versions the latest version for iPhone 4s was iOS 9.3.6

iPhone 6 Plus isn’t compatible with iOS 17 the lates version was iOS 12.5.7