Bengali Hindus
Bengali Hindus () are an ethnic, linguistic, and religious population who make up the majority in the Indian state of West Bengal and Tripura. In Bangladesh they form the largest minority. They are Bengalis adherents of Hinduism, and are native to the Bengal region in the eastern part of the Indian subcontinent. Bengali Hindus speak Bengali, which belongs to the Indo-Aryan language family and adhere to the Shakta and Vaishnava traditions of their native religion, Hinduism. There are significant numbers of Bengali-speaking Hindus in different Indian states.
Burmese Indians
Burmese Indians are from an array of ethnic backgrounds. There are Tamils from Tamil Nadu, Telugus from Andhra Pradesh and Marwaris from the Marwar region of India's Rajasthan state as well as Bengalis hailing from the Indian state of West Bengal as well as the present-day independent nation of Bangladesh. 
Prior to the expulsion of Indians, there were also Malayalis from Kerala, Odias from Odisha, Punjabis from the state of Punjab who are mostly Sikhs and two groups of Gujaratis, both Gujarati-speaking Parsis and Gujaratis proper who are mostly Hindus or Muslims by faith hailing from the state of Gujarat. 
All can and were able to communicate in Burmese due to years of assimilation and lack of education in languages other than English. Other languages used by Burmese Indians include Tamil, Telugu and small pockets of Malayalam speakers.