Hi
1.What are the requirements for creating multi source universe?
If you want to display data from multipule data bases (SQL,Oracle, etc) into the reports, then you can create multi-source universe.
For that you need to create multpile connections and pointing to one universe (Muilti-Source).
http://scn.sap.com/docs/DOC-22055
https://www.youtube.com/watch?v=6QHhFSNLDG0
https://www.youtube.com/watch?v=hDd-U8VVGzM
https://www.youtube.com/watch?v=BNb2b2T7tuc
2.it supports or not creating universe on top of sap and non sap data sources? if it supports.how its possible?
Find the below links for more info.
http://events.asug.com/2012BOUC/0915_Building_a_Multi_Source_Universe.pdf