- Raja Ram Mohan Roy founded the Atmiya Sabha in 1815 in Calcutta (now Kolkata). This was an association of friends who discussed religious and social topics. - He later founded the Brahmo Sabha in 1828, which was subsequently renamed Brahmo Samaj. This was a significant socio-religious reform movement that advocated for monotheism and opposed idolatry, caste system, Sati, etc. - Prarthana Samaj was founded in 1867 in Bombay by Atmaram Pandurang, Mahadev Govind Ranade, R.G. Bhandarkar, and others, inspired by the Brahmo Samaj. Raja Ram Mohan Roy was not its founder. - Arya Samaj was founded by Swami Dayananda Saraswati in 1875 in Bombay. Raja Ram Mohan Roy was not associated with its founding.