The scta-1.6.exe file you have requested: Tools and Utilities / Server Tools / SCTA v1.6 (windows) - 586.71kb is not available. Perhaps try browsing all files for the game Quake III Arena and upload any files you want to share or are missing. This is the only information we could locate:
It enables the server admin to have MUCH more control over the server than would normally be possible. While it does add features and options, it can be configured to behave EXACTLY like a nomral Q3TA server. SCTA/SCQ3A is an enhancement for Q3 Team Arena servers.