All the relevant stuffs such as conversion, missionaries etc pertaining to John Allen Chau is available on net and I am not going to to talk about it. Here, I want to bring in to your notice a case of Stainislaus Vs State of MP (link is here https://tinyurl.com/y8wusyl3). In this case, Supreme Court held that
“‘Propagation’ in Article 25 of Constitution of India means transport from one person to other person or one place to other place. Force, fraud, inducement of allurement takes away the free consent from the would be converted which is not in consonance with Art 25 of Constitution of India.”
Stainislaus filed appeal against his conviction under various sections of ‘Madhya Pradesh Freedom of Religion Act 1968’ and relevant law in Orissa. Supreme Court rejected his appeal and held in favour of the state. After this SC pronouncement Arunachal Pradesh Legislature passed a Bill modelled exacly on the MP and Orissa Acts. A private MP Shri O. P. Tyagi presented similar Bill before House of People which, if passed, would be applicable to whole of India. (I still wonder why none of “Hindu Nationalist” govt want to reintroduce such Bill.) Unfortunately, parliament dissolved because Morarji Desai resigned and Bill lapsed. However, Arunachal Bill passed with President’s assent.
Ironically, Ministry of Home Affairs, Govt of India allowed foreign tourist free visit of Andaman & Nicobar islands in June 2018, to promote tourism, for which they would have required registration at Foreigners Registration Officer. This approval indirectly opened doors for such “soul harvesters”.