In 1840, Duff returned to India. At the Disruption of 1843, Duff sided with the Free Church. He gave up the college buildings, with all their effects and established a new institution, called the Free Church Institution. He had the support of Sir James Outram and Sir Henry Lawrence, and the encouragement of seeing a new band of converts, including several young men born of high caste. In 1844, governor-general Viscount Hardinge opened government appointments to all who had studied in institutions similar to Duff's institution. In the same year, Duff co-founded the "Calcutta Review", of which he served as editor from 1845 to 1849. In 1857, when the University of Calcutta was established, the Free Church Institution was one of its earliest affiliates, and Duff would also serve in the university's first senate. These two institutions founded by Duff, i.e., the General Assembly's Institution and the Free Church Institution would be merged later to form the Scottish Churches College. After the unification of the Church of Scotland in 1929, the institution would be known as Scottish Church College.