Can I update iso 14 on iPhone 6 Plus?

You mean you can update it but you wont get all the new features that the 14 update provides...from experience...And if you have alot of apps on it like my daughter has you cant update at all...from experience.

Ya know the oldest iphone I have is the 4. I play with all of the iphones we have. It just doesnt get all the features and sometimes theres no room to update. All anybody has to do is try an update it. I have the 5s, all the 6s, and 7s, meaning the plus ones also and the xs. The only one that fully updated was the xr my other daughter has.... meaning she got the full 14 update features. Therefore if this person wants a full update this person needs a newer iphone. I have one of the sevens right now and is updated to 14. No offense you can say what you want but Ive done it.

No. iPhone 6 cannot run anything later than iOS 12.

No, it can not be updated to iOS 13, or 14 at all.

The OP’s question was correctly answered by the very first reply, your additions are pointless.