In which one of the following countries, is Tamil a major language?

The correct answer is Singapore. Tamil is one of Singapore’s four official languages and is accorded formal status there, giving it institutional presence in education, media and government functions [1]. Singapore also hosts several hundreds of thousands of Tamil speakers and a visible Tamil linguistic community, underscoring its role as a major language in that country [2]. By contrast, Mauritius—while granting Tamil constitutional recognition—has it as a minority/heritage language rather than one of the country’s primary official languages [1]. Myanmar and Indonesia have Tamil-speaking migrant or diaspora groups but do not recognize Tamil as a major national language.

Sources

1. [1] https://www.americantamilacademy.org/?page_id=2280
2. [2] https://plc.sas.upenn.edu/languages/tamil