As you probably know, the Nagori are a dairy-farming Muslim caste from Rajasthan & Gujarat, and being traditionally involved in the dairy business, the Tea they make is known as ‘Nagori chai’ since its made with Milk of a much higher fat content and thicker consistency. I guess the marketing and branding for this tea was done by Rajasthani Muslim migrants in Bombay - since ethnic branding of food/drinks has proven to be a good time-tested option.