Oracle 12c Client Compatible with 9i Server?
This is from behind the Oracle registration wall:

Client / Server Interoperability Support Matrix for Different Oracle Versions (Doc ID 207303.1)

Client Version: 12.2.0 or 12.1.0
Server Version: 9.2.0
Supported: No #3


Where:

#3: An ORA-3134 error is correctly reported when attempting to connect to this version.


So I would not expect it to work at all.