If you are facing an error like this:

limit has been reached for requested resource NBU_POLICY.MAXJOBS.CatalogBackup

Most probably this is an issue about NBU 6.5.3. If you can look at the following bug report page:

http://seer.entsupport.symantec.com/docs/318079.htm

The easiest way to resolve the problem is to restart netbackup daemons.

Another method is explained in the above document.