Inner Line Permit is an official travel document issued by the Government of India

Government of India

The Government of India, officially known as the Union Government, and also known as the Central Government, was established by the Constitution of India, and is the governing authority of the union of 28 states and seven union territories, collectively called the Republic of India...

 to allow inward travel of an Indian citizen into a protected/restricted area for a limited period. It is obligatory for Indian citizens from outside those states to obtain permit for entering into the protected state. The document is an effort by the Government to regulate movement to certain areas located near the international border of India. This is a security measure and it is applicable for the following states:

• Arunachal Pradesh
  Arunachal Pradesh
  Arunachal Pradesh is a state of India, located in the far northeast. It borders the states of Assam and Nagaland to the south, and shares international borders with Burma in the east, Bhutan in the west, and the People's Republic of China in the north. The majority of the territory is claimed by...
  
   – Issued by the Secretary (Political) of the Government of Arunachal Pradesh
  Arunachal Pradesh
  Arunachal Pradesh is a state of India, located in the far northeast. It borders the states of Assam and Nagaland to the south, and shares international borders with Burma in the east, Bhutan in the west, and the People's Republic of China in the north. The majority of the territory is claimed by...
  
  . It is required for entering the India
  India
  India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
  
  n state of Arunachal Pradesh through any of the check gates across the inter-state border with Assam
  Assam
  Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...
  
   or Nagaland
  Nagaland
  Nagaland is a state in the far north-eastern part of India. It borders the state of Assam to the west, Arunachal Pradesh and part of Assam to the north, Burma to the east and Manipur to the south. The state capital is Kohima, and the largest city is Dimapur...
  
  .

• Mizoram
  Mizoram
  Mizoram is one of the Seven Sister States in North Eastern India, sharing borders with the states of Tripura, Assam, Manipur and with the neighbouring countries of Bangladesh and Burma. Mizoram became the 23rd state of India on 20 February 1987. Its capital is Aizawl. Mizoram is located in the...
  
   – Issued by the Government of Mizoram
  Government of Mizoram
  The Government of Mizoram also known as the State Government of Mizoram, or locally as State Government, is the supreme governing authority of the Indian state of Mizoram and its 8 districts...
  
  . It is required for entering the India
  India
  India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
  
  n state of Mizoram through any of the check gates across the inter-state borders.

• Nagaland
  Nagaland
  Nagaland is a state in the far north-eastern part of India. It borders the state of Assam to the west, Arunachal Pradesh and part of Assam to the north, Burma to the east and Manipur to the south. The state capital is Kohima, and the largest city is Dimapur...
  
   – It is mandatory for a mainland Indian citizen entering the state of Nagaland through any of the check gates across the inter-state borders.

• Sikkim
  Sikkim
  Sikkim is a landlocked Indian state nestled in the Himalayan mountains...