Hi Ravi,
HR audit can be done by preparing check list, whether all things are followed according to checklist.
# Recruitment
Like position is closed within how many days (<30 days or more)
Reference check is done
whether pre-employement medical done
whether all documents collected
whether PF, gratuity, supperannuation, etc forms are filled at the time of joining.
So on you can prepare such check list for each fuction like training, induction, manpower, Appraisal, etc.
Regards,
Varsha