I have a requirement like I need to upload multiple version of document from file system with meta data stored in a separate database.

    I have created a  console to do this operation,i can upload the document and it metadata but I cannot change the "CREATED" field value without creating a new version. any suggestion is appreciable.

   Thanks in advance.

You can use SPListItem.SystemUpdate().

Example: http://microsoft-techies.blogspot.ru/2014/05/itemupdate-and-itemsystemupdatefalse.html

hi Alex,

thanks for the reply ,I have tried that but Created field is not updating as the systemUpdate is to perform action without changing the readonly field (Created)

Why you need change "Created" field for items? 
Please read the following article:  http://blogs.technet.com/b/vedant/archive/2009/04/03/updating-created-and-modified-information-in-sharepoint-document-libraries.aspx