Super-NZB‘s Delete RAR/PAR Files options are located at:
Setup Menu > Settings > Misc
If you don’t need the RAR and PAR files after extracting your file(s), you can have SuperNZB automatically delete them, or move them to the trash. This option will also delete the ancillary files associated with the RAR archive: SFV, SRR, NFO, and NZB. This will only delete the NZB file which is sometimes listed in the NZB that you downloaded from the search engine.