Hi,
Its all depends on your network and your account team are the best guys to tell which software is good to run in your environment.
Here are few which I would like to say:
Cisco 6001 Switches:
1-Latest
7.0(4)N1(1)
6.0(2)N2(5)
2-
Stable release:-
6.0(2)N2(3) --Cisco Suggested release based on software quality, stability and longevity.
HTH
Regards
Inayath
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