Can I grow Delonix regia in Scotland?

I don't think you'd be successful outside but it would be OK in a conservatory or large heated Greenhouse. We can't grow it in the soft south. Unless , of course, you are in one of those balmy corners with the Gulf Stream to protect you? I'd try it for as long as it had room! It would need lots of light to flower.

You could probably grow it as an indoor bonsai but it wouldn't survive the winter outdoors. A lovely looking tree though so it's worth a try.

Have a look at these past questions and comments, they may give you all the advice you need, copy and past this into your web browser

http://www.growsonyou.com/plant/Delonix_regia

or alternatively click on Delonix regia next to 'this question is on' at the top where the date of the question is.
After looking at the other comments, I think you will get all you need from there

In order to germinate Delonix regia sucessfully you need to:

1) Boil one quart of water
2) Turn off heat and add seeds
3) Leave seeds in boiling water for 3 - 5 minutes
4) Add 1/2 qt. of of cool water
5) Let soak overnight
6) Germinate in light soil (half perlite/cactus mix or fast draining soil) in 4 to 6 inch container.(preferably terracotta pot)
7) Pot must be in very hot (above 85 degrees F / 30 degrees C. during day with min temp of 69 degrees F / 21 degrees C. at night) sunny spot to germinate or it may rot.
8) They will usually germinate in about 4 to 7 days.

This is my personal experience growing these trees.
NOTE: they are very sensitive to over watering especially when young.