GST amendment notification updates taxable goods codes and adds diethylcarbamazine, effective from early June 2021. The notification amends Schedule I by substituting the entry for serial number 259A with commodity code 9503 and inserts Diethylcarbamazine as serial number 231 in List 1; these changes are deemed effective from 2 June 2021 under the Odisha Goods and Services Tax framework.