Find your Drupal version
To find your site's Drupal version, go to
http://server_URL/admin/reports/status. The Status report page opens, and the Drupal version is to the right of the Drupal variable in the table of your site's parameters.
Here is an example of a Drupal 8 site:
Here is an example of a Drupal 7 site:
Here is an example of a Drupal 6 site: