Kerala, the state mentioned in the article, is surprisingly distinct from the rest of India. It has some of the highest literacy rates in India (something like 92%) and an HDI comparable to developed countries[1].
Historically, Kerala had trade relations with the levant, and Rome from antiquity, and has hosted a large jewish diaspora[2]. Kerala has also had its share of christian "immigrants", starting with the story of St.Thomas, to traditions about Syrian Christians settling in Kerala during the 4th century AD. [3] Plus, the traditional christian church in Kerala is the Jacobite Syrian Orthodox church [4], with its official language of liturgy being Syriac (a derivative of Aramaic).
Similarly, there is a very ancient muslim tradition in Kerala [5], including the very first mosque in India.
Kerala is also famous for a lot of its contribution to Hindu thought [6], while some traditions are markedly different from the rests of India[7].
Kerala also has its own martial art, which arguably predates the more famous chinese martial arts. [8]
Finally, IIRC, Kerala was never completely under British rule, but I'm not completely sure on this point.
All in all, a very fascinating place.
[1] https://en.wikipedia.org/wiki/Kerala_model
[2] https://en.wikipedia.org/wiki/Cochin_Jews
[3] https://en.wikipedia.org/wiki/Thomas_of_Cana
[4] https://en.wikipedia.org/wiki/Malankara_Jacobite_Syrian_Orth...
[5] https://en.wikipedia.org/wiki/Islam_in_Kerala
[6] https://en.wikipedia.org/wiki/Hinduism_in_Kerala