An ISI License is an official approval granted by BIS that allows manufacturers to use the ISI Mark on their products. ISI stands for Indian Standards Institution, the former name of BIS. The ISI mark is a symbol of trust, quality, and safety. When a product carries the ISI mark, it means it has been tested and verified according to specific Indian Standards (IS codes).
https://bis-certifications.com..../a-guide-to-bis-cert