The Power Mac G5 computer is not supported for use with any version of Mac OS X Server 10.2, or any earlier version of Mac OS X Server. Mac OS X Server 10.3 will be supported on Power Mac G5 computers.
Power Mac G5 computers require Mac OS X 10.2.7 (G5), which is made specifically for this computer. Mac OS X 10.2.7 (G5) cannot be installed on other computers, and other versions of Mac OS X 10.2 (both server and client) cannot be installed on the Power Mac G5 computer.