Hi @sujanyakj ,
on ACS 5.8: " ... when you create a new Administrator, you have an option to choose the type of Identity Store for the password type. The new Administrator is authenticated based on this password type. The password type can be Internal Administrator, AD or LDAP. The default value of ALL the existing Administrators is AdminsIDStore ... ".
I never see this option on ISE.
Hope this helps !!!