The '6.2 Client' is the client that is compatible with EQEmu version 6.2 and later and marked the point where the developers stopped 'chasing Live'. The exact build date (from logs/dbg.txt) is:
Code:
Starting EverQuest (Build Aug 4 2005 15:40:59)
It doesn't correspond to a retail release, so mostly only long time followers of EQEmu who made a copy on that particular patch day will have a copy.