In the backup server one of the tape has frozen and I want to move this frozen tape to bad_tapes pool. Please let me know how to do this. I am using veritas netback
It depends. If there are unexpired backups on it, you cannot. That is, if the tape is not completely empty, Netbackup does not allow to change the volume pool.
Why would Netbackup still keep unexpired backups on a frozen tape? Tape typically becomes frozen because of write errors, but some data theoretically could be still readable, so during the eventual restore Netbackup will try to read the frozen tape.
To empty the tape, or to be more correct to "mark all backups on the tape as expired", you need to know the proper media server:
If the tape is frozen and empty, you can simply unfreeze it, and at this point you can move it to another pool. Then you should freeze the tape again, as a good practice. The thing you are trying to do seems so complicated because it is against the normal method of use of this software. The status "frozen" is designed specifically to do what you need, to mark "bad tapes" and avoid using them for backups ever again. The "frozen" status is not used for anything else in Netbackup, and the tapes do not unfreeze automatically until your manual intervention. It is normal for a tape to sit frozen in its default pool for years, there is nothing wrong with it.