This question has been asked a number of times in multiple forums - is a Non-Unicode system possible on a ECC 6.0 or ERP 6.0 system.
Well the answer is both yes and no! Depending on the code page type of system you can have your ECC 6.0 system as a Non-Unicode or a Unicode System. You can club the UNICODE Conversion to a release upgrade as well. And depending on the code page type of your source release you can combine your upgrade together with the UNICODE Migration.
The following are the scenarios for code-pages:
1. With SAP NetWeaver 2004s support for existing MDMP systems is stopped. SAP systems with more than one system code page and/or with Blended Code pages must be converted to Unicode using reliable tools delivered by SAP. Thus you cannot have MDMP or Blended code pages on ECC 6.0 systems and hence you need to convert to UNICODE.
2. However, single code page systems are allowed on NON-UNICODE SAP Systems based on ECC 6.0 (NW04s).
However, if you have JAVA Stacks talking to ABAP Stacks (via JCo connections) you may face problems if your ABAP stack is NON-UNICODE. For details on this please check SAP Note 794411.
All new installations based on NW04s will be UNICODE installations only.