Attempting to reinstall CS6 Standard on McOS 10.12 after a drive failure.

"not able to reinstall CS6 Standard"

What exactly do you mean?

Were you able to install the software, but cannot activate it? or... what? Any specific messages, etc?

"no longer show up on my account"

If you had registered, they should be there. Mine, for instance, lists my CS5.5 and CS6, along with the respective serial numbers and a download link for installers. What you cannot do, tho, is deactivate a CS install from the account page... that was never a thing you could do on the account page "back in the day" before... only CC apps can be.

Even if they are not listed, you should be able to register your CS5.5 and CS6 serial number now on your Products page.

If you get an error message trying that, make sure you write it down so you can talk to Adobe again (yah, I know)

By the way, the installers that they link to are the exact same ones available on the ProDesignTools site;

https://prodesigntools.com/adobe-cs6-direct-download-links.html

I suggest you download the CS6 installer from there and try again.

I recently did this exact install as a test a couple of months ago on an older laptop, and it was successful, although the online activation didn't work: I had to use the alternative method (send a code and receive a response code) offered. It worked like a charm. If you bump up against a "you've maxxed out your installs" message, only a call to Adobe to Reset your activation count is the answer (yah, I know). Alternatively, if you don't need it on the second Mac anymore, Deactivate that one from the Help menu; that should free up one install, but I hesitate doing that in case it screws up being able to Reactivate it later.

Last century software like Pagemaker is irrelevant to this topic. It has been dead for ages and I highly doubt it can run much less install on a modern computer anyway.

Adobe owns the software.  Non-genuine software can imply that you bought a bogus license to use it from a 3rd party vendor who was not authorized to sell it. Or your serial number was shared with multiple users thus violating the terms of use agreement.   Unfortunately, nobody here can help you with that. 

With respect to your current HD, did you wipe it clean or does it have old software on it?  Use the Adobe Cleaner tool to remove all traces of old software including old Flash Player and Acrobat Reader.  Then restart your computer. 

https://helpx.adobe.com/creative-cloud/kb/cc-cleaner-tool-installation-problems.html

Use the original installation disks or downloads you received at purchase.  Keeping in mind that legacy Creative Suite is unsupported and installers don't work on Sierra, High Sierra or Mojave without terminal workarounds, see link below. 

https://helpx.adobe.com/creative-cloud/kb/install-creative-suite-mac-os-sierra.html

Good luck!

Log-in to your Adobe account and click this link https://account.adobe.com/products

-my account shows my registered products going back to CS5

Have you ever used a different email address?

Adobe no longer supports CS6 from 2012, and nobody here can help with an account problem