40 Tb FS Backup using PR site Networker on Tap drive LTO-9 i want to restore that backup on DR Site

so no-one experienced within your team with Networker therefor as if you have another networker backup server being involved, then you would have to use scanner to re-populate the DR backup server with the contents of the tape(s) involved, using the scanner command, either by scanning the media information only (hence you only could perform a full saveset recovery only, not being able to see nor select individual files and/or directories to restore) or also the actual client index data (being able to select and restore individual files/directories).

What are we even dealing with here? A single system Networker server only making backups of itself using a single tape drive or small tape library, or rather a networker backup server and tape infra making backups of clients? Any networker storage nodes involved or does only the backup server have tape drives? As typically you would want to run the scanner command on the system where the tape is loaded into.

You might wanna use scanner -m to first only make nw knwo which savesets are on the tape and then might only need to scan in the client index info by using -i. Often the preferred way would be to first use nsrck -L7 to restore the client index from tape, so to make the client index available again, but often a client index might not be located on the same tapes that are needed to be scanned in, therefor -m and -i would still be good enough but more time consuming (the more files the longer).

Something needing to be very, very careful with is to not ever label such a tape that comes from another backup server. Before inserting it into the drive or tape library, might wanna set the physical write-protect switch. So in case of a tape library it is nsrjv CLI using -lnv (load-no-mount + verbose option) which only loads a tape into a drive but does not try to mount it (which it would not be able to do anyways as it will not know the tape (yet)).

If it is a single tape drive, connected directly to a system, then insert the tape into the drive manually. But please state what we are dealing with here?

Assuming you have a rather current networker version also and a Dell support contract to be able to access KB articles:

https://www.dell.com/support/kbdoc/en-us/000227522/networker-using-the-scanner-utility?lang=en "NetWorker: Using the scanner utility"

https://www.dell.com/support/kbdoc/en-us/000094628?lang=en "How to Recover Data from Tape Outside of Retention Policy"

https://www.dell.com/support/kbdoc/en-us/000080186?lang=en "NetWorker: How to use scanner to rebuild both the media and the online file indexes for a client?"

Ignore KB parts that use uasm to restore data directly from tape with scanner. Use scanner -m and then -i first to make data known to NW and only then use the recover command to actually restore data. The contents should match with the same mminfo queries on the original backup server.

If you intend to restore all data from the saveset in question, then a saveset restore would also be way faster than doing a file based restore as that has a way higher overhead, especially if millions of files are involved.

@shanway , From the question I am guessing that you are pretty new to NetWorker. I would recommend the following steps and a video to help you with that step.
1. Identify the savesets(data) that you need restoring - user the NMC.
2. Do a NetWorker DR at your DR site. - https://youtu.be/GD0GgrRd3-Q

3. Reconfigure the JB - https://youtu.be/bKvdhzavK6U
4. Do a saveset restore of the data use the NMC. I am guessing no system restore in scope.

And I definitly hope the FS backups is not a block based backup that has been cloned to tape.