There are certainly no inscriptions or literature that I am aware of but the group of Syrian Christians of Indian state of Kerala are certain proof that St. Thomas the Apostle came to India. The form of Christianity that the British, French and Portuguese’ Catholic and Protestant versions are much, much different from the Syrian version. Moreover, The grave of St. Thomas the Apostle is in Mylapore, Chennai(an Indian city) and a few churches and crosses built by St. Thomas the Apostle still survive to this day. An incident where the Syrian Christian minority is mentioned;when Pedro Alvares Cabral of Portugal incited violence in Calicut, where the Portuguese massacred Arab traders and Syrian Christians. There is also evidence that St. Thomas came to Taxila(a famed Indian centre for learning) but failed This incident is mentioned in ‘Land of the seven rivers’ by Sanjeev Sanyal. The overall information is in the second link and the evidence that St. Thomas was in Taxila is in the first link 1]: http://odysseuslahori.blogspot.com/2013/03/st-thomas-in-taxila.html?m=1 [2]: herehttps://en.m.wikipedia.org/wiki/Thomas_the_Apostle..