how can i get free real backlink on my .com site. and link must be do follow??? tell me plz.
I do not quite understand your post.
What exactly are you attempting to do?
Are you attempting to add a link from one domain to another?
You build links the same way, whether you site is .com, .org or anything else. There are already a number of threads on link building, including [this one, so I suggest you have a read of them. You will also find a wealth of useful information in the sticky threads at the top of this forum and you can download Google's [URL="http://support.google.com/webmasters/bin/answer.py?hl=en&answer=35291&topic=2370419&ctx=topic"]SEO Starter Guide](http://www.sitepoint.com/forums/showthread.php?870902-2012-Latest-Link-Building-Techniques).
Please search, both on this forum and via your favourite search engine, and I'm sure you'll find all the information you need. However, if you still have a specific question after that, please feel free to post again.
Meanwhile, thread closed.