You usually do not use nsrim but nsrck. From the CLR:

"nsrim is not normally run manually. However, the command?s modes can be 
modified such that normal users may run the command while retaining root 
privileges; see nsr(1m) for more details.
...
"When the savegrp(1m) command launches nsrim at the end of its task, it checks 
the timestamp of the file /nsr/mm/nsrim.prv. If the timestamp of this file is 
greater than or equal to 23 hours, nsrim marks all save sets that are passed 
their browse and retention policy as recyclable. If save sets need to be 
monitored for their browse and retention policy more frequently (for example, 
if savegrp(1m) is run more frequently than every 23 hours), nsrim -X should be 
set up as a cron(1m) entry, or should be run manually."
...
nsrim ?X Check the consistency of the data structures of the save set with the 
data structures of the volume. This is only required after a NetWorker crash."


nsrck however takes care about index cross checking, as explained.

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