Chicory is a common additive in Indian Coffee. A quick search in wikipedia reveals that it is usually 20-30% in coffee powder. Can coffee be made solely out of chicory? Does the chicory root contain caffeine or just the flavor profile of coffee?
Chicory has no caffeine, hence it reduces the caffeine content in brewed coffee. It also thickens the brew.
While people may want to consume raw chicory for health reasons, this is irrelevant for coffee, as it contains roasted, not raw, chicory.
Roasted chicory root (which is what you are adding to coffee) contains no caffeine.
What chicory does is add a nice, roasted flavor to coffee, which is desireable either for cultural reasons, or to offset the bitter flavor of over-roasted low-grade coffee beans. Originally, it was also added because it was much, much cheaper than coffee. That's not true anymore, even in India as far as I know.
Proper New Orleans or Vietnamese coffee also contains a lot of chicory.