Depending on the vintage of your computer and the software limitations
of the combined configuration, you may have to consider looking into
your system install-restore disc (whatever it is) and either use Pacifist
to extract just the Safari browser and use Pacifist to get the software
from the DVD and install it from the desktop (not run DVDs installer)
or see if there is a suitable Safari browser for your older OS X in PPC
from these. A browser newer than your OS X supports won't work.
Perhaps you could go back as far as Safari prior to Panther 10.3.9, here
http://support.apple.com/downloads/#safari
{Downloads for Safari later than Snow Leopard 10.6.8 are AppStore items.}
Or get a different supported browser for older PPC by looking into
archives for TenFourFox, or iCab, or very old FireFox 3.x. online.
The latest TenFourFox would be OK for Tiger/Leopard.
Good luck & happy computing! 🙂