The diocese covers 10,486 square kilometers, the entire state of Tripura. Agartala is the biggest town in the state.
Main ethnic groups living in the territory: Debbarma, Darlong, Uchoi, Jamatia, Halam, Reang, Garo, Kaipeng, Bengali, Molsom, Mog, Tripura, Adivasi
Bengali, KokBorok, and other languages and dialects are spoken.
The beginning of the Catholic faith in Tripura dates back many centuries. Jesuit Father Ignatius Gomes made the first reference to the Christians of Mariamnagar village in Agartala, which he visited in 1683. Father P. Barbe visited from Chittagong in 1843. Pioneer Holy Cross missionaries Fathers Louis Augustine Verite and Beboit Adolphe Mercier visited Agartala in 1856 and administered sacraments to the Christians in Mariamnagar. Priests established a permanent residence in Mariamnagar in 1937, and in 1939 the first parish in Tripura was erected in the village. The first permanent church, currently the temporary Cathedral, was blessed in 1952. Because of geographical proximity, the Archdiocese of Dhaka continued to tend to the spiritual needs of Catholics in Tripura until the erection of Haflong Prefecture in 1952. In 1969, the Prefecture was upgraded to become Silchar Diocese, with Bishop Denzil D' Souza as its first ordinary. Silchar covered the states of Mizoram and Tripura, and Cachar District in Assam.
Pope John Paul II decreed the erection of the Diocese of Agartala on Jan. 11, 1996, separating it from Silchar (now Aizawl), and appointed then-Father Monteiro its first ordinary. Bishop Montiro was ordained and installed on May 26, 1996. The Diocese of Agartala is dedicated to Christ, the Light of the World. St Francis Xavier is its patron and its motto is "Lead us Onward."
Villages and small towns are administered by panchayat and municipalities, respectively. These local bodies are elected.
The diocesan area is well connected by roads. Agartala has an airport.
Annual per capita income is 20,357 rupees (US$438 as of November 2009). The terrain, soil and climate of Tripura are ideally suited for rain-fed horticulture. Various kinds of fruit including pineapple, jackfruit, orange, lychee, cashew nut, coconut, lime, and lemon are produced in abundance. Rubber, tea and other cash crops also are produced in the diocesan area.
Bamboo grows across Tripura. The area also has vast reserves of natural gas.
Government and private operators provide extensive telecommunication facilities in the diocesan area. The diocese is well served by local cable TV networks.
73.19 percent literacy rate