If u have got it done from HEC and Foreign office, you have two options. one is to get it attested from Qatar Embassy but i don't think Karachi Consulate will attest it, you have to send it to Islamabad but check with the consulate.

Other option is to bring them here and get it attested from Pakistan Embassy here and Ministry of Foreign affairs Qatar.

If your docs are attested from Qatar Embassy in Pakistan, ou can get it attested directly form Ministry of Foreign Affairs Qatar and skip Pak Embassy.
Its your choice what you want to do