If you live in Northern Thailand then Thai Immigration in Chiang Mai will be able to assist you with a visa extension such as a Thai tourist visa or extend your Thai marriage visa or Thai retirement visa for you. You can also do your 90 day reporting at Chiang Rai immigration offices.
Below is a map to the Thai immigration offices in Chiang Rai. Their contact numbers such as their telephone number, fax number and email is attached. Note the operating hours of the office and always ensure that you get in there early for visa assistance.
Thai Immigration Chiang Rai
117 Amphoe Mae Sai Changwat Chiang Rai
Fax: 0-5373-1008-9 ext. 24
Opening Hours: 8:30am-4:30pm Monday to Friday
Service Area: Provinces of Chiang Rai, Phayao