Hi Rajdeep,
SAP FIORI 2.0 and version 2 applications are different.
fiori 2.0 is a new version of full fiori framework. It is not yet released when I checked last time.
You can find more information about this here. "http://news.sap.com/sap-fiori-2-0/"
It is mentioned there that it will the new face of SAP S/4 HANA.
here is a video also of the fiori 2.0 demo "https://www.youtube.com/watch?v=jn787YijXBw"
Version 2 of the existing application is different. It just provides some new features and look and feel for particular application.
Regards,
Sarbjeet Singh