Where can I download Acrobat 9 Pro Extended

You must follow the very important instructions otherwise you get ACCESS DENIED.

https://prodesigntools.com/all-adobe-cs5-direct-download-links.html

if you purchased from and registered with adobe, check https://helpx.adobe.com/in/download-install/kb/downloaded-older-app.html  for info on how to download non-current adobe programs.

once you download, if you're having trouble finding your file(s), https://helpx.adobe.com/x-productkb/global/find-downloaded-file-app.html

if that fails AND you've (a) registered your software with adobe or (b) can provide proof of purchase, using a browser that allows popups and cookies, contact adobe support during pst business hours by clicking here and, when available, click 'chat', https://helpx.adobe.com/contact.html

for more info on adobe's 5/2019 policy on downloads, https://prodesigntools.com/adobe-limits-software-downloads.html and there are still some direct download links that work (https://prodesigntools.com/adobe-limits-software-downloads.html#ddl).

Adobe do this. We have no links at all, and providing them is their job. Public downloads have largely been removed but support (if they were trained in it) could provide links to some. I suspect this particular link is gone forever though.