Anything around the slash will work with sysdba if sysdba is allowed by the OS.
This is an OS issue, so the the OS matters. For unix boxes, some kind of sudo script can be appropriate - the key is logging the event to somewhere the user can't change it.
Also look at the purpose of sysoper: http://docs.oracle.com/cd/B28359_01/server.111/b28310/dba006.htm
Because i need a customized user for data uploading process only where shutdown immediate and startup restrict access is required.
A special database administration role that permits a database administrator to perform STARTUP, SHUTDOWN, ALTER DATABASE OPEN/MOUNT, ALTER DATABASE BACKUP, ARCHIVE LOG, and RECOVER, and includes the RESTRICTED SESSION privilege."