My first recommendation would be to upgrade to FC4 or FC5, you may find that the drivers you need are automatically detected by a more recent version.
RealTek also provides downloadable drivers specifically for FC4 and FC5, RCEL and a generic tarball for any version of Linux (kernel version 2.2.14 and up) here:
http://www.realtek.com.tw/downloads/...&Software=True
which was the first hit on a simple Google search for "Linux realtek ac97 driver".
Hint: You will get more help from the Linux community if you do a little bit of work for yourself before asking someone else to do it for you.