Is there any kind of food which works like adhd medications and which really helps a person with adhd ? is it a stimulant ? is it a good alternative ?

Nope, sorry: No, there are no foods which are as reliable or effective for adhd as stimulant medications. Caffeinated beverages like coffee would be the closest, but aren't as focused or as easily titrated as stimulant medications.

Heal your brain: Adhd is not a clear cut problem, but anything that you do to improve your nutrition should help. Specifically, avoid processed foods and artificial ingredients. Many people also have food allergies so trying an elimination diet (look it up on google) is worth trying. Also take fish oil and vitamin d supplements since they support nerve function.