[1] The Orthodox parishes in the North and North Eastern states of India, Kuwait in the Persian Gulf region are included in this diocese, viz.

Chhattisgarh, Madhya Pradesh, parts of Maharashtra, West Bengal, Odisha, Bihar, Sikkim, Tripura, Jharkhand, Assam, Nagaland, Mizoram, Meghalaya, Arunachal Pradesh, and Manipur.

The Diocesan headquarters is in St Thomas Ashram , Bhilai, Chhattisgarh.

This was consecrated by the then Malankara Metropolitan Baselios Mar Thoma Mathews I, the Catholicos in 1986.

The first Metropolitan, Kayalath Dr. Stephanos Mar Theodosius was buried in St Thomas Ashram, Bhilai.

After Mar Theodosios's death in 2007, the diocese came directly under the control of the Malankara Metropolitan Baselios Marthoma Didymos 1.

In 2009, Dr. Joseph Mar Dionysius took charge as the Metropolitan of Calcutta .

Metropolitans 1)Kayaleth Dr.Stephanos Mar Theodosios (1979-2007) 2)Baselios Marthoma Didymos 1 (2007-2009)(As Malankara Metropolitan ) 3)Dr. Joseph Mar Dionysios (2009-2022) 4) Alexios Mar Eusebios (2022- Present) Assistant Metropolitans 1)Puliyeeril Dr. Geevarghese Mar Coorilose (2007-2009) The Diocesan Metropolitan is also the Director of St. Thomas Orthodox Church Mission, one of the pioneer missions outside Kerala.

The Mission is mainly concerned with Education and Social Development.

The diocese manages 25 schools, one Arts and Science Post Graduate & B.Ed.

25) Kuwait Mar Gregorios Orthodox Maha Edavaka

43) St Thomas Orthodox Mission Congregation