in netbackup with sql agent,snapshot is created while taking the backup?
you might need to provide detail info about your question
I just want to know when Netbackup SQL agent takes the backup of live database,then it creates asnapshot of database and then take backup of that?
Depends. Normally it does stream-based backups. If licensed for Snapshot Client and properly configured then you can do snapshots.
Will Restore -- where there is a Will there is a way
You have asked previously what happens during SQL backup.
See this post: https://www-secure.symantec.com/connect/forums/what-happens-during-live-sql-server-backup
Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links
@WR:So if not configured for snapshot client ,then how does it takes the backup?
I don't know details of how Microsoft handles that. Best to ask on SQL Server forum.