While the article is specific to Calcutta and the Bengal region, the concept of adda is prevalent in almost the whole of India. Every city, town and even village has a corner (or many such corners in cities) which usually attracts people who come to have a casual and relaxed discussion about anything under the sun and eat some local delicacy.

Check out the movie Brahman Naman (it's on Netflix in the US). This is a coming of age, sex comedy set in 1980s Bangalore and shows the concept of "adda" many times where teenage/college boys hangout, ogle at girls and discuss esoteric quizzing topics.