Indian constitution too have no rights to segregate Manipur

The demand for a separate State or Union territory by some MLAs of the Manipur State Legislative Assembly can never become reality as there is a provision that protects the state of Manipur in the Constitution of India. The Government of India will certainly have second thoughts before taking any decisions that affect the territory of Manipur as it had entered an agreement with the government of India before the commencement of the Constitution of India.
It is on record that Manipur merged with the Indian Union on October 15, 1949. The then Maharajah of Manipur Bodhchandra Singh signed an agreement with the then representatives of the Government of India, viz. V.P. Menon, Advisor to the Government of India, and Sri Prakash, Governor of Assam at Redland in Shillong on September 21, 1949. Leaving aside the argument on the legitimacy of the merger agreement, it is on record that the erstwhile Asiatic nation merged to the Indian Union after signing an ‘Agreement’. This agreement was signed six months before the Constitution of India came into force. As per an official document with the Government of India, the area of Manipur then was 8, 620 sq. miles (22,325.7 sq. Km). It is recorded in the “White Paper on Indian States” printed by the India Press, New Delhi, and Published by the Manager of Publications Delhi, 1950. The population of Manipur was then 5,12,000.
Interestingly, Article 363 of the Constitution of India says that “ Notwithstanding anything in this Constitution but subject to the provisions of Article 143, neither the Supreme Court nor any other court shall have jurisdiction in any dispute arising out of any provision of a treaty, agreement, covenant, engagement, sanad or other similar instrument which was entered into or executed before the commencement of this Constitution by any Ruler of an Indian State and to which the Government was a party and which has or has been continued in operation after such commencement, or in any dispute in respect of any right accruing under or any liability or obligation arising out of any of the provisions of this Constitution relating to any such treaty, agreement, covenant, engagement, sanad or other similar instrument.
Now the question arises here, can the Government of India apply Article 3 of the Constitution of India to the state of Manipur? Article 3 empowers the Parliament of India to form a new State by separation of territory from any State or by uniting two or more States or parts of States by uniting any territory to a part of any State; or by increasing the area of any State; or diminish the area of any State; or alter the boundaries of any State.
Again, under Article 131 of the Indian Constitution, the Supreme Court has original jurisdiction in any dispute between the Government of India and one or more States; or between the Government of India and any State or States on one side and one or more other States on the other.
So, if any decision is taken by the parliament to divide Manipur under Article 3, it can be definitely considered as a dispute between the Govt. of India and the Government of Manipur, which can be intervened by the Supreme Court. And under Article 363 of the Constitution of India, the Supreme Court does not have jurisdiction in any dispute arising out of any provision of a treaty, agreement, covenant, engagement, sanad, or other similar instruments which were entered into or executed before the commencement of the Constitution. As of today no interpretation of this article has been made by the Apex Court, it can be assumed that the application of Article 3 by the parliament can be ruled as unconstitutional unless the President of India exercises its power under Article 143 of the Indian Constitution.
On the other hand, if refers to the UTI Possedetis Juris, of International Law, even the parliament of India cannot alter the boundary of Manipur.