For example when Tamil Superstar Rajini kanth became popular in Japan, those Japanese fans required the Rajinikanth movies with subtitles with their Japanese language. As he become more popular with the new movies Japanese people are searching for his old movies too. So the Tamil film producers who made the Rajinikanth movies are looking for people who knows Tamil and Japanese to make subtitles to re-release their movies in Japan market.
So those people who can directly translate Tamil to Japanese and the translation must be in time too to capture with the scene and must be readable before the next scene or sentence must come. So the sub title maker must be more intelligent than the normal Tamil translator or normal Tamil interpreter to capture the audience most of the top Tamil actors and Tamil actress movies are made with sub titles to market them all over India other than the Tamil speaking Tamilnadu and the Pondichery states.
For the foreign Tamil cinema market Tamil movies are made with English language sub titles. So now you understand the need of the sub title maker jobs in the Tamil cinema industry.
Mean while there are plenty piracy Tamil movie makers are in the South Asia where they make sub titles in the Malay and Bahasa Indonesia to market those movie in this region. They use the local people who know to make sub titles in the Malay and Bahasa Indonesia from Tamil.
Recently Tamil Mega serial makers, Children story makers and Short TV serial makers too were start to publish their products with English language sub titles to capture more market and earning.
As the Tamil media industry expands world wide the need for sub title makers from Tamil to other language will have good job opportunity not only in India but world wide too.