Hi @AbhijeetKulkarni,
> I am trying to build replication between Oracle and MS-SQL geodatabases ...
FYI, this capability is available in ArcGIS, it's called geodatabase replication.
> Has anyone succeeded in building sync system where source and destination are ... different versioning enabled?
I don't think this is possible. The purpose of replication is to "copy/transfer" content from one geodatabase to another; the same content. What you propose: 'converting' one method of versioning to another is not supported as far as I'm aware.
Hope this helps,