I'm currently doing a research for my mum and her husband(my stepfather).Don't seem to be able to get any accurate info I need though. Hope you people here could help. thank you.

They've just sold off their business in the states and are planning to move to thailand and start a small business there (maybe a resturaunt or something) The problem is my mum's 43 and her husband's 41.

I know retirement visa requires u to be at least 50yo.. is there any other alternatives? Or is there any other way her husband can eligible to apply for permanent residence in thailand?

*my mum also holds a thai citizenship, and her husband is a french. (if it helps?).