If you define first-grade in Australia/NZ as NSWRL (1908-94), ARL (1995-97), SL (1997) and NRL (1998 onwards):
- Tyran Smith (South Sydney, Nth QLD, Hunter Mariners, Auckland, Balmain, Wests Tigers, Canberra).
- Darrien Doherty (Penrith, Western Suburbs, Canterbury, Illawarra, Hunter Mariners, Adelaide, Nth QLD)
both played for 7 clubs. I believe this is the record. I'd be surprised if you can find another RL player since 1908 who played for 7, let alone 8.
There's several players who've played first-grade for 6 clubs:
- Brett Kimmorley (Newcastle, Hunter Mariners, Melbourne, Northern Eagles, Cronulla, Canterbury)
- Phil Blake (Manly, South Sydney, North Sydney, Canberra, St George, Auckland)
- Kevin Campion (Gold Coast, St George, Adelaide, Brisbane, NZ Warriors, North QLD)
- Graham Mackay (Western Suburbs, Penrith, Syd Roosters, South QLD, Gold Coast, Manly)
- John Carlaw (Hunter Mariners, Melbourne, Balmain, Wests Tigers, NZ Warriors, St George/Illawarra)
- John Elias (Newtown, South Sydney, Canterbury, Western Suburbs, Syd Roosters, Balmain)
- Dale Shearer (Manly, Brisbane, Gold Coast, Sth QLD, Syd Roosters, Nth QLD)
- Scott Wilson (South Sydney, North Sydney, Canterbury, Gold Coast, Western Reds, North QLD)