If your directory uses nonstandard objectclasses to define users and groups you need to change the appropriate iim_ldap.* parameters, replacing inetorgperson and groupofuniquenames with your values.
See LDAP and User Registration Configuration Parameters for a list of LDAP parameters.
Open iim.conf.
See iim.conf File Syntax for instructions on locating and modifying iim.conf.
Search for and replace inetorgperson with the object class used to define users in your directory.
Search for and replace groupofuniquenames with the object class used to define groups in your directory.
Save and close the file.