Here is the original Papal Bull from St. Pius the Xth in the creation of Kottayam Diocese in Kerala. Note that it was created, explicitly, for the Knanaya people (also known as the Southists). The Pope decided to create the separate diocese (Vicariate) to take care of their spiritual needs of the dissidents. I think, the demand, now, is to extend that authority to outside of India which should not be a problem in my opinion.
English:
For the future record of the matter. (note that, throughout this text, the Holy See uses the “royal We” to refer to itself)
In the duty of governing the Universal Christian flock (that has been) divinely entrusted to Us, We think it belongs to Us in particular to set for Churches boundaries which both are desirable to those presiding over them and answer to the good of the faithful. With this goal in mind, to better provide for the faith and piety of the Syro-Malabarican people, We have decreed to set up a new Apostolic Vicariate in their region. In this nation Our predecessor of fond memory Pope Leo XIII–by a letter similar to this one dated 28 July 1894–set up three Apostolic Vicariates (i.e. Trichur, Ernakulam, and Changanacheri), and for these three he considered and arranged for three officials, selected from among those Syro-Malabarican people–to be put in charge.
But now, because the three Apostolic Vicars of these Vicariates named above have assiduously sought from Us–by mutual consent and though a letter dated March 1st of this year–that a new Apostolic Vicariate be drawn up in the city commonly called Kottayam to better provide for the spiritual needs of those regions and counsel the minds of dissidents, We, having maturely and carefully looked over all (“omnibus” for the typo “ominibus”?) the important details with the venerable bretheren of our Holy Roman Church (VV. FFr. NN. S.R.E.) the Cardinals of the Sacred Congregation for the Propagation of the Christian Name according to the business of the Oriental Rite, have decided to graciously receive these sorts of requests and demonstrate the pledge of Our benevolence to the aforementioned nation.
Wherefore, by motu proprio (lit. “by his own impulse”, but really a legal phrase indicating a written command of the Pope), out of sure knowledge and in the fullness of our power, we separate all the Suddists (Southists) parishes and churches from the twofold Apostolic Vicariates of Ernakulam and Changanacheri and establish them in a new Apostolic Vicariate for the Suddists (Southists) people in the city commonly called “Kottayam”. Which, therefore, takes in all the Churches and Shrines reaching to the Deaconry of Kottayam and Kaduthuruthy in the Apostolic Vicariate of Changanacheri along with the Suddist (Southists) Churches of the Apostolic Vicariate of Ernakulam.
We want and command these things, decreeing (“decernentes” for the typo “decermentes”) this letter to forever be firm, valid, and legal, and will win and obtain its own full and integral effects, and will most fully favor in all things and in every way those to whom it concerns now and in the future, and should be judged so in the future, and considered null and void if it happens at a later date to be changed–knowingly or unknowingly–by anyone regardless of their authority. But nothing shall prevent the right of Our own Apostolic Chancery or of other Apostolic Constitutions in contradiction, from nullifying this decree.
Given at Rome at St. Peter’s, under the ring of the fisherman, 29-August-1911, the 9th year of our pontificate.