After being found along the coast of the Konkan, the seven couples decided to stay there and begin a new life. In a strange country, they found themselves alone, but they soon became acquainted with the locals. Over time, they and their descendants spread to 142 villages, where each generation lived in a different village.
They were nearly entirely without holy scriptures following the shipwreck, as they had nothing left. They didn’t have any synagogues. Some have guessed that they came to India before the Second Temple was destroyed, but according to Rabbi Jonathan Bernis of The Jewish Voice, this is incorrect. “They did not celebrate Hanukkah, leading many to speculate that their arrival in India “actually pre-dated the destruction of the Second Temple,” Bernis wrote.
And, as Nathan Katz points out, Hanukkah is not a particularly notable holiday: its celebration is essentially built around the fact that it occurs at the same time as Christmas. You should make an exception for Hanukkah, seeing as it is the least important Jewish holiday. It is a 20th century holiday because it falls in the 20th century. A well-known, brand-affiliated holiday celebrated around the world.
Source: https://www.livemint.com/Sundayapp/8wjqC8MxAzd3KrGrQb69rL/The-curious-case-of-the-Bene-Israels.html