Sandip, has a good first step.
You also NEED to exclude the BE installation directory, the beremote.exe process on both clients and servers as a centralized exception. If backing up to disk, may want to exclude BKF's too and the B2D folder.
There is a KB article if you hunt around for recommended AV settings when using BackupExec. I'm pretty sure if you go to the support site and search the KB you can find it with little fuss.