Even as revenues keep increasing, a standard rate of Goods and Services Tax (GST) would be fixed, said Union minister, Arun Jaitley. The standard rate could be anywhere between 12 per cent and 18 per cent slab, he said. Cement and auto parts are the only useful items in the 28 per cent slab and soon Cement will be brought into a lower slab, he said. At present there are 28 items in the 28 per cent slab. Soon only harmful and luxury items will be under this slab, he said.