It looks like there's only one repository causing trouble, probably one that you added explicitly yourself? You might want to check that the server is up and running by contacting the project and asking if they are having any issues.
Otherwise, you can try to change the location of the server manually by editing the file located at /etc/apt/sources.list. Find the entries with the country code ir and change them to something else. For good measure, create a copy of this file before making any changes to it. Also, you will need elevated privileges to edit this file. See this guide for more details: