Check this, try to call them.
Oman Embassy , Qatar
Ibn Alqassim Street No. 41, Villa No. 7, Alhilal Area, Doha, Qatar
Phone: +974-670-744 / +974-670-746
Fax: +974-670-747

or check this link for the map.

http://oman.visahq.com/embassy/Qatar/