In general, this isn't possible. NDMP doesn't specify a data format. So netbackup clients don't know how to read the datastream.
In the particular case of Netapp, they use a format that is pretty similar to a Solaris 'ufsdump'. So you can probably use 'ufsrestore' to recover it with some work.
https://forums.symantec.com/syment/board/message?board.id=21&thread.id=36270
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Darren