How to connect oracle 6i form with oracle 12c,19c Database ?

[admin]

Conn Sys As Sysdba

alter profile DEFAULT limit PASSWORD_REUSE_TIME unlimited;

alter profile DEFAULT limit PASSWORD_LIFE_TIME unlimited;

---------------Case Sensitive Login----------------------
alter system set sec_case_sensitive_logon=False;

---------------To Allow export of tables with no row--------------------------
ALTER SYSTEM SET DEFERRED_SEGMENT_CREATION=FALSE SCOPE=BOTH;

add this line in SQLNET.Ora File

SQLNET.ALLOWED_LOGON_VERSION=8
SQLNET.ALLOWED_LOGON_VERSION_SERVER=8
SQLNET.ALLOWED_LOGON_VERSION_CLIENT=8

EXEC DBMS_XDB.SETLISTENERLOCALACCESS(FALSE);


Connect sys as sysdba

shutdown immediate;
startup mount;
alter system enable restricted session;
alter system set job_queue_processes=0;
alter system set aq_tm_processes=0;
alter database open;
ALTER DATABASE CHARACTER SET INTERNAL_USE UTF8;
shutdown immediate;
startup;
SELECT value$ FROM sys.props$ WHERE name = 'NLS_CHARACTERSET';