Hi Matija,
You can find the list of supported Operating Systems and SQL Anywhere versions here:
http://scn.sap.com/docs/DOC-35654
We have not tested, nor do we support Adaptive Server Anywhere (now called SQL Anywhere) version 6 on Windows Server 2008. It my or may not work for you.
The current supported versions of Adaptive Server Anywhere / SQL Anywhere are 12 and 16.
You can register to get a (free) copy of the version 16 developer edition here:
http://www.sap.com/campaign/na/usa/CRM-XU13-CST-SQLDEVEDM/index.html
--Jason