IGST rate amendment substitutes tariff classification and adds Diethylcarbamazine, changing applicable IGST treatment. The notification amends Notification No.1/2017-Integrated Tax (Rate) by substituting the Schedule I entry for serial number 259A with tariff heading '9503' carrying the 5% rate, and by inserting Diethylcarbamazine as serial 231 in List 1; the amendments are effective from 2nd June, 2021.