It’s been interesting to find Bengalis from the Bengali speaking states in India, namely West Bengal and Tripura working in the Indian restaurant sector, aka Mamak’s in Malaysia. Usually Bangladeshi’s were known to be a diaspora all over, but their Indian Bengali counterparts are following suit for very little money.
Not surprisingly Bengali Muslims from Nadia and Mushirdabad dominate, although Hindus are being found too. Bengali migration internally to Mumbai, Delhi and Bangalore is well known.
A paper is lurking somewhere for an enterprising scholar from the academic industrial complex of CU JU and PU.