You can take IELTS tests in Norway through Folkeuniversitetet.
HOW TO CONTACT FOLKEUNIVERSITETET
Studieorganisasjonen Folkeuniversitetet
Rolf Wickstrøms vei 15
0484 Oslo
Email: ielts@folkeuniversitetet.no
On the Folkeuniversitetet website you can find specific information about IELTS:
IELTS
IELTS test cancellation and refund
Do you need to prove your English language level for a UK Visas and Immigration (UKVI) application?
IELTS is on the UKVI list of approved Secure English Language Tests (SELT). If you need an IELTS test result as part of your application to UK Visas and Immigration (UKVI), you will need to take your test at a specific test location authorised by UKVI.
CAMBRIDGE ENGLISH
How to register for Cambridge English exams in Norway
PROFESSIONAL AND UNIVERSITY EXAMS
Professional and University exams are for people who wish to obtain a British professional qualification, such as accountancy and law or a university qualification, such as MBAs and other university degree examinations, including those related to distance learning programmes.
Please consult the Folkeuniversitetet website for specific information about where you can sit professional and university exams in Norway.