Try soaking of seeds in 10-4 M GA3 for 8 hours.

If the outer layer of the seed is too hard, rubbing the seed surface with sand-paper (scarification) may help. I have personally tried it for Peltophorum pretocarpum and Adenanthera pavonina. Next, you may rinse the seeds in sterile distilled water, followed by either 0.1 % HgCl2 or sodium hypochlorite for 10 minutes, repeat distilled water and then place on appropriate medium.

Seed coat is hard so require presowing treatment, usually rubbing in sand paper and soaking over night in fresh water would be appropriate. Since seed quantity is not problem therefore percentage of germination ahs not been giver due attention.

thanks

Soaking seeds of delonix regia in water over night and soaking in boiled water until it cools would cause uniform and high germination rate for the crop within four to five days. 

What is your aim with this seeds? Research or crop production?

I think the hard seed coat prevents water imbibition and so first you scarify the seeds without damaging embryo.  then soak the seeds in GA3 below 500ppm for 24 hrs.

Mechanical scarification in one of the longitudinal extremities, followed or not by water soaking. Chemical scarification in sulfuric acid is equally efficient. Delonix regia seeds present high germination rates with both treatments.

Seeds may allow in the soil for 2-3 years without germinating and it usually takes 12-349 days to germinate. To break this dormancy seeds are collected, boiled in hot water for at least 24 hours then planted in unshaded nursery beds, they germinate within 5-10 days. Seedlings grow rapidly and can be transplanted when 20-25 cm high

soaking in boiling water for 8-10 minutes and than keeping over night enhances the germination. some also tried GA3 @300-500 ppm soaking overnight. but scarification is required for better results either chemical or mechanical

soaking in normal water for 48 hrs gives best results, tested by me.