Hi Vinothini,
See the doc link below:
https://techdocs.broadcom.com/us/en/ca-mainframe-software/automation/ca-workload-automation-esp-edition/12-0/reference/statements/release-statement-identify-successors.html
ADD
Add the specified jobs to the list of jobs currently specified in RELEASE statements.
So if you only use ONE RELEASE statement, then you needn't use ADD option. But if there are multiple RELEASE statements in the same JOB, then ADD may be required.
Hope this helps,
Lucy