The steps would be to follow the process outlined in the Disaster Recovery section of the troubleshooting guide.
- Rebuild master server to same NetBackup version (and same name).
- Since you have encrypted tapes (you don't say how) but if via KMS, then you will need to recreate the KMS keys to enable the tape to be read (as long as you have the various passphrases you should be good).
- Perform a catalog recovery
- Recover the CA certificate for the master server using the DR package (this can also be done during the initial build of the new master server).
If you are unable to recover the catalog tape (by the way, it is not recommended to encrypt the catalog backups), then you will have to try recovering the MSDP pool to the newly built master. There's a good article from our friend Marianne where she decribes this process - see https://vox.veritas.com/t5/NetBackup/Import-MSDP-images/m-p/462337.
I would be reaching out to Veritas support in either case to assist with which ever process you go with.