Please anyone can help me to find free Copyscape software ?
It might take a little extra effort, but Google itself is a good tool for searching duplicate content. I use it for that all the time.
Surely this has been answered in your other thread? http://www.sitepoint.com/forums/showthread.php?1039607-Duplicate-Content-Checking
this question has been asked and answered dozens of times in this forum. Please do a search using your favorite search engine or search the forum for similar threads.