How to find drupal 6 ubercart Persian translation?
You can find the direct link here:

http://ftp.drupal.org/files/translations/6.x/ubercart/ubercart-6.x-2.9.fa.po

In case you're interested (and for future reference) that comes from the Ubercart translation downloads page on Drupal.org.

You're pretty lucky, it was only generated 2 days ago!