REMOTE_LOGIN_PASSWORDFILE specifies whether Oracle checks for a password file.

NONE: Setting this parameter to NONE causes Oracle Database to behave as if the password file does not exist. That is, no privileged connections are allowed over nonsecure connections. Therefore, privileged users must be authenticated by the operating system.
EXCLUSIVE: (The default) An EXCLUSIVE password file can be used with only one instance of one database. Only an EXCLUSIVE file can be modified. Using an EXCLUSIVE password file enables you to add, modify, and delete users. It also enables you to change the SYS password with the ALTER USER command.
SHARED: A SHARED password file can be used by multiple databases running on the same server, or multiple instances of a RAC database. A SHARED password file cannot be modified. This means that you cannot add users to a SHARED password file. Any attempt to do so or to change the password of SYS or other users with the SYSDBA or SYSOPER privileges generates an error. All users needing SYSDBA or SYSOPER system privileges must be added to the password file when REMOTE_LOGIN_PASSWORDFILE is set to EXCLUSIVE. After all users are added, you can change REMOTE_LOGIN_PASSWORDFILE to SHARED, and then share the file. This option is useful if you are administering multiple databases or a RAC database.

If you want to use OS Authentication, you must enable operating system authentication of an administrative user:
Create an operating system account for the user.
Add the account to the OSDBA or OSOPER operating system defined groups.
The at the command line you can access the database as "CONNECT / AS SYSDBA"
If you want to create users in the database, that's a different story. The user id must be the same on the OS layer as it will be in the database. Then you connect to the database with the SYSDBA system privilege. but you must set REMOTE_OS_AUTHENT initialization parameter to TRUE and set OS_AUTHENT_PREFIX to "".
LS
"640KB ought to be enough for anybody." - Bill Gates, 1981

Oracle LazyDBA home page