Thanks Don.
It stands for Taj Mahal monument in Agra India, one of the 7 wonders of the world.The most visited tourist destination of India.
But Taj also denotes crown worn by ancient Indian Kings.
So it is used to convey something that is prime.
Used by Businesses in India to indicate premium stuff.
Example is Taj premium 5 star hotel in Mumbai India.
As regards pronunciation, it will be Taj itself.