Nikon- s6ii, Windows 7 and Photoshop CS6 compatibility problem

Your software and OS are too far out of date (Dead & buried) to use with the Z6ii!

You will be limited to using JPGs from the camera.

Even Nikon's own software Nikon-NX Studio requires Windows 8 or 10.

https://www.nikon.com/news/2021/0304_soft_01.htm

CS6 is only compatible with Camera Raw up to version 9.1.1. (So 12.4 is useless for you!)

https://helpx.adobe.com/camera-raw/kb/camera-raw-compatible-applications.html

Lightroom (all Versions) Do not use Camera Raw. The CR 'engine' is incorporated within Lightroom and can only be 'updated' by updating Lightroom itself.

The Nikon Z6ii requires Minimum Lightroom-Classic Version 10.1 (A subscription to the Photography Plan required)

https://helpx.adobe.com/camera-raw/kb/camera-raw-plug-supported-cameras.html

The Adobe DNG Converter for Legacy support of old software requires Windows-10 (So no luck there either!)

https://helpx.adobe.com/camera-raw/using/adobe-dng-converter.html

The Answer-  New Computer, new software. To match your shiny new Nikon!

See: https://helpx.adobe.com/camera-raw/kb/camera-raw-plug-supported-cameras.html

IF your camera is so new, it isn't listed here, nothing you can do for the time being. 

Every time Canon (or Nikon, or Sony etc) release a new cameras, they do this stupid trick of making yet a new proprietary raw file that everyone outside the company, including Adobe need access to so they can 'hack' the tiny differences to support that new proprietary raw. You the customer get to wait and are forced to use the manufacturers raw converter until this all takes place. It is silly but that's how it has been for decades. Some companines are faster to do this than others, but the facts are, every 3rd party raw converter manufacturer has to go through this silly dance. Complain about this to your camera company. 

Update: Camera raw still says v 7.0.0.308 on photoshops about menu and in Lightroom despite my attempts to install version 12.x yesterday.  This is after a computer restart.

I had to download 12.x directly instead of from the photoshop menu prompt because photoshop complains about not being able to reach servers due to firewalls. LR says that it's up to date.