Solaris 9 is no longer available as a free download.
Older releases of Solaris 10 are no longer available as free downloads, either.
If you want it directly from the company, your only recourse is if you happen to have any support contract credentials with Oracle. You could then log a Support Request (S.R.) that asks for the company to send you the software on CD media. They would pull it out from their internal archives and eventually get it to you.
I can think of another alternative, but it's not a free alternative:
You can haunt your favorite online auction web site (for example, eBay) and purchase a full original media kit of CD's and manuals. As I type this, there are a few such kits avaiable at eBay, various Sol9 releases, both for SPARC and for x86.