Oracle 9i to 12c Replication I have an old Oracle Forms solution that accesses a 9i database and I have been asked if it's possible to replicate to an Oracle 12c database server, with the intention of using Fusion until a new application is built.

Is it possible to replicate between these two versions? Or is there another way to achieve an active-active replica between the two servers? i.e. log shipping etc.
Please consult the Oracle Update and Migration Guide

There is no direct upgrade path, for your data a export/import might work. 
Your old Forms application will not work, Oracle 10.1 was the last version that could run old 6i Client/Server Forms,IIRC