How to provide option to select geographic part for content
Try the Location module. It will help  you to attach location info with nodes. More details from the module's project page:


  The Location module allows real-world geographic locations to be associated with Drupal nodes, including people, places, and other content. The Location module allows admins to collect addresses, geocode them (translate addresses to lattitude/longitude), and associate locations with Drupal nodes and users. Location data is automatically used to generate GeoRSS within your existing RSS feeds.