I'm trying to find out a way to preserve historic data. (mandated 10yr retention) Our company has just merged with another that uses netbackup and I would like to bring it under one solution.
Is it possible to migrate indexes from netbackup into networker?
Nope. What I would do is migrate NBU to VM and archive it and run it only if needed for restore. Prior to that make sure to document all steps needed to make this work (at least for next 10 years). If that is not possible, then you will need to migrate this data which means restore it with NBU to some temp space and do backup with NSR.