I want to make a jsff to use css file which existing in UCM conten server. Is there any way to do. Additinionally, this application will be portal fragments in Webcenter Portal, i mean i will deploy it as a library jar
Take a look at this tutorial chapter: http://docs.oracle.com/cd/E21764_01/webcenter.1111/e10273/createconnect.htm#BGBDDHAA
It describes how to add a repository connection (UCM) to a WebCenter Framework application, how to browse files, and finally, how to add a content item to a resource (and how binding will look like).
For usage of CSS in JSF see also this: http://www.mkyong.com/jsf2/how-to-include-cascading-style-sheets-css-in-jsf/