...do bwr model 6's have 8 srv's, 4 erv's and 1 target rock like other bwr models...
...do they function in the same way...
The type of SRV isn't model specific, it's plant specific. Fermi had 15 Two Stage Pilot Operated SRVs with no ERV/PORVs. Target Rock is a Model type not necessarily a valve type.
The amount and type depend on the utility's design philosophy.
Mike