Muslim nikkah done abroad, now want to register it in Malaysia

There is a muslim couple where the man is a Malaysian and they did their nikkah at the woman's country. The man has stayed in her country for over 2 years as he has the nikkah certificate over there.

Now they plan to move to Malaysia and want to know what the process is like to register their nikkah here. Since he didn't obtain his permission to marry abroad letter from JAIS, they know they will have to face some fines as they had broken some rules.

Does anyone here face this situation before or know how the proceedings will be? What should they expect and can they instead register the nikkah in Kelantan/Perlis to have a better chance of not having a big issue? Because I know JAIS is way more strict compared to Perlis or Kelantan's islamic department in terms of marriage. And if so, is he able to even register in those states even if his IC is Selangor?

Also their nikkah had the wife's Wali over there, so no issue for this section.

Not much information is out there on google, so any advice is great thanks.