User Ids are created based on department and country. There are not created based on Employee ID.
For UAR, we want to keep manager as first stage but since user id are not based on employee ID system is unable to fetch manager data in GRACUSER.
Can anybody tell me what approach we should take?
Employee ID and User Id don't need to match. The HR employee record needs to contain infotype 0105 subtype 001 relationship which captures the User Id.
It's been a while since I've been on the tools (someone else jump in). .. The connector configuration can then list the user data source as HR which will read the information in during the object repository sync job.
If standard does not work for your workflow agent determination rule then you can always create a customer rule with ABAP code to retrieve the manager information.