Re: How to download all the documents within a site in alfresco at desired location ?
A couple of tips for you, Prashant. This question does not demonstrate that you've done anything to help yourself. It does not describe what you've tried or where you are stuck. You'll get more help with potentially more actionable advice when you show that you've put some effort into the problem and you get more specific about exactly what you need.
With all of that said, writing a script to export content should be straightforward if you are a coder. My advice is to choose your favorite programming language and then grab a CMIS client that works with that language and write the export yourself.