Wash the rice thoroughly and set aside to soak for at least one hour.
In a large covered pot, bring 8 cups water and the salt to a boil. Add the rinsed rice and boil on high heat uncovered for about 6-8 minutes, or until the rice has slightly softened.
Drain the rice in a colander, rinse with lukewarm water, and set aside while you prepare the yogurt and egg mixture.
In a large mixing bowl, combine the saffron, yogurt, eggs and 5 tablespoons of oil and mix thoroughly.
Gently fold in the parboiled rice and mix until all the of the rice is mixed with the golden yogurt and egg mixture.
Place the remaining 1 tablespoon of oil in a non-stick pot and add the rice mixture to the pan.
Wrap the lid with a clean towel and place on top of the pot. This will allow the rice to steam.
Allow the rice to steam over a medium-low to medium heat for 45 minutes.
While the rice is cooking, prepare the barberries by gently melting the butter and then adding the barberries, sugar and saffron water. Stir over low heat for about 2-4 minutes until the barberries have turned bright and glistening. Take care to not burn the berries. Set aside.
After 45 minutes, remove the rice pot from the heat, and carefully but swiftly invert the rice over a platter.
Garnish with the barberries and pistachios and serve right away.