Were Western adventurers to Indian surprised to find people recognisably practising Christianity?

The Portuguese who first arrived in India were unfamiliar with Hinduism, and initially thought that it was a strange but vaguely recognizable form of Christianity, and rested some hopes on an alliance with the local "Christians" against the Muslim traders. Proposed reasons for this include the existing legend of the kingdom of Prester John who was supposed to have a powerful realm of Eastern Christians beyond the Muslim world, iconography of goddesses that may have come close enough to be familiar to images of Mary and Jesus, and possibly the similarity between the names Krishna and Christ, but no doubt with a handy serving of wishful thinking thrown in as well. This initial confusion seems to have hidden the fact that there actually were some Indian Christians from making much of a splash. Later, when the Portuguese had some local supremacy in India, especially Goa, the "Thomas Christians" under Portuguese control were forced to conform to Roman Catholic practices and were treated with at least some hostility.

What I know about the era comes mostly from reading on the spice trade, especially for this answer from Nigel Cliff's "The Last Crusade -- The Epic Voyages of Vasco da Gama." I found it an interesting and informative read. There may, however, be some specialists on the region and time period here who have criticisms of the work, and I defer to them in advance.