CiviCRM module "Group-Based Prising" doesn't work in Joomla
Can you confirm that's the correct directory for extensions by going to Administer menu » System Settings » Directories and looking at the Extensions directory listed there?  It may also need to be updated from the Drupal location if you copied the database.  If there's a token like [civicrm.files] you can click the question mark in the blue circle in the text at the top of the page to see what that token resolves to.
If the directory is correct, it's likely a file permission issue.