The details for the Thai Embassy in Iran is listed below. Call them before you visit the embassy to ensure that they are open and able to process your applications.
IRAN (Islamic Republic of Iran)
Royal Thai Embassy
Baharestan Avenue, Park Amin-ed-Dowleh No.4
P.O. Box 11495-111, Tehran
Tel: (98 21) 753-1433, 753-7708
Fax: (98 21) 753-2022