Authorization for Oracle DB

Hi All I have Oracle DB configured for RADIUS authentication and now having issue with Authorization part. My use case is as follows: 1. Oracle DB sends RADIUS AUthentication request to RADIUS server, which performs authentication against LDAP. 2. After succesfull authentication it retrieves group and role information for authenticated user and that group and role information it has to sent as part of authorization. 3. After receiving group and role info Oracle DB should provide him access of schemas associated with group and role. I am facing issue during Authorization. If anybody know Authorization steps then please let me know. Any help is highly appreciated. Thanks Arvind Kumar Gupta