I want to put k2 content module as "Latest addition" for a particular category, but the issue its templating. This module isn't looking nice with the looks point of view. I want it to use the same template as other modules from default template has. Is there a simple way to achieve that.

By my opinion the best module for display k2 items is the JXTC k2 content wall. It requires some knowlegde on css and html but it can do magic :)