@Indignation
"Following their expulsion from Iberia in 1492 by the Alhambra Decree, a few families of Sephardi Jews eventually made their way to Cochin in the 16th century. They became known as Paradesi Jews (or Foreign Jews)."
https://en.wikipedia.org/wiki/Cochin_Jews
Maybe these Jews in India practiced a different religion before the Sephardic Jews arrived
They probably keep themselves separate because they doubt the religious and biological line of the Sephardic so called Jews who made up a new religion