How do I get F6 on a Mac to click into the address bar on Chrome?
The following works for me under macOS 10.13.5 and Google Chrome 68.0.3440.106.

Under System Preferences > Keyboard > Shortcuts > App Shortcuts I added Google Chrome's Open Location… menu command, as shown in the image below. Note the ellipsis at the end has to be there!

On an Apple wireless keyboard with default System Preferences > Keyboard settings, I can press F6 when in Google Chrome and it does the same as the default ⌘L does.

On a MacBook Pro with default System Preferences > Keyboard settings, I have to  press FnF6 when in Google Chrome and it does the same as the default ⌘L does.

On a MacBook Pro while changing the default System Preferences > Keyboard settings, i.e when checking [√] Use F1, F2, etc. keys as standard function keys, I can press F6 when in Google Chrome and it does the same as the default ⌘L does.