The Karnataka Khadi Gramodyoga Samyukta Sangha (Federation) located in Hubli is certified as the sole institution to supply national flags for the entire country, by the Khadi and Village Industries Commission (KVIC) and in conformation with the standards laid down by the Bureau of Indian Standards (BIS).
Hubli has the unique privilege to hold forth the national flag for the rest of the nation.
For complete information read the following articles.
Why all national flags will be ‘Made in Hubli’
Nation’s identity is woven here
The flag town
BIS certification for sangha
Tricolor: Handspun and handwoven
Information on Flag of India at Wikipedia
Karnataka Khadi Gramodyog Samyukta Sangh (Federation)
India - 580023.