In 1986, the Parliament amended the Constitution through The Constitution (Fifty-Fifth Amendment) Act, 1986 the Government of India intended to grant the status of state to the Union Territory of Arunachal Pradesh. It was proposed by the Governor considering the sensitive locality of Arunachal Pradesh and the Governor declared that the new state shall have special obligation to maintain law and order in the State and in fulfilling its functions. The Constitutional Amendment was modeled on December 23, 1986 which inserted Article 371 H under the Constitution of India which confers special status to the State of Arunachal Pradesh. The Governor is bestowed special authority to maintain law and order in the State and conduct the activities after discussion with the Council of Ministers. To abide by Constitutional provisions the Central Government enacted The State of Arunachal Pradesh Act, 1986 on December, 1986 which came into force on February 20, 1987.
On the day of commencement of the enactment, the State of Arunachal Pradesh came into existence which was the former Union Territory of Arunachal Pradesh. The Act amended Schedule I of the Constitution which inserted entry 24 ‘Arunachal Pradesh’. The sitting members of the Rajya Sabha which represents the Union Territory of Arunachal Pradesh shall be considered to have appropriately elected under Article 80(4) of the Constitution to fill seats allocated to the State of Arunachal Pradesh in the Rajya Sabha and the term of the members remains unchanged. In the State of Arunachal Pradesh two seats are allotted in the Lok Sabha and the Schedule I of the Representation of Peoples Act, 1950 shall be amended in accordance with the provisions of the Act. The Parliamentary constituencies of the Union Territory of Arunachal Pradesh shall devolve to the State of Arunachal Pradesh and the provisions of the Delimitation of Parliamentary and Assembly Constituencies Order, 1976 shall be interpreted accordingly.
The maximum number of members to be included in the Legislative Assembly of the State of Arunachal Pradesh shall be sixty who are elected through direct election. Out of sixty seats, fifty nine seats are to be members of the Scheduled Tribes. The Election Commission shall distribute the seats to single member territorial constituencies, allocated to the Legislative Assembly of the State of Arunachal Pradesh and delimit them according to the provisions of the Constitution. While delimiting the constituency special attention shall be given to geographically compact areas, physical aspects, boundaries of administrative areas, ability of communication and convenience of the public. The seats reserved for the Schedules Tribes shall be situated in the locality where the ratio of the population shall be largest compared to total population. The Act provides for a common High Court for the States of Assam, Nagaland, Meghalaya, Manipur, Tripura, Mizoram and Arunachal Pradesh which shall be called as the High Court of Gauhati.
Until the Governors (Emoluments, Allowances and Privileges) Act, 1982 comes into effect, the payments and salaries of the Governor of Arunachal Pradesh shall be determined by the President. The President shall conclude the grants-in-aid of the State of Arunachal Pradesh with regard to revenues and share of the State in the excise duties of the Union, estate duty and income tax. The property and assets held under the Union Territory of Arunachal Pradesh shall be transferred to the State of Arunachal Pradesh. The Act provides for the constitution of Advisory Committee to aid in the discharge of functions and guarantee just and impartial management of all persons coming under the provisions of the Act.
Additionally, the Act amended Article 210, Article 239 A and Article 240 of the Constitution of India from the commencement of the legislation. The Act also modified Armed Forces (Special Powers) Act, 1958, Government of Union territories Act, 1963 and the North- Eastern Council Act, 1971 as provided under the Act.