Rain Carbon uses green petroleum coke (GPC) as its primary feedstock in the production of calcined petroleum coke (CPC), which is an essential raw material in the anodes required during the electrolytic process of aluminium production. The company also imports CPC for blending at its Vizag facility.

Under the Supreme Court's ruling, India's calcining industry will be permitted to import up to 1.4 million metric tons of GPC annually; the ruling also permits India's aluminium industry to use up to 500,000 tons of imported CPC per year.