migrate admin, auth not working in oracle 12c

While i have shifted my models from sqlite to oracle 12c i am able to migrate custom models to oracle database while i am not able to access admin as i havent migrate admin auth inbuilt models, so i execute below command and got error
python maanage.py migrate admin
django.db.utils.databaseerror ora-00955 name is already used by an existing object

looks like i am not able to migrate the admin, auth table.

Pleas suggest any solution