[4] Jamir is the grandson of Jungshinokdang, who in the late 19th century, had the providential opportunity to meet the American Christian Missionary Rev.

He did his early education in Mokokchung, at Kolkata's Scottish Church College for his intermediate in arts,[5] and higher studies at Allahabad University from where he subsequently obtained his B.A.

[6] Jamir was a member of the negotiation body that held talks with Prime Minister Jawaharlal Nehru in 1960 leading to the establishment of Nagaland as a state within India.

[8] He was appointed the Parliamentary Secretary to Jawaharlal Nehru, then Prime Minister who was also in charge of the Ministry of External Affairs.

Having won the previous terms as Member of Parliament uncontested, Jamir faced the electorate in the 1971 Indian general election pitted against Kevichüsa Angami from the newly formed United Front of Nagaland.

[11]In October 1972, Jamir was arrested along with former Nagaland Chief Minister T. N. Angami, and others on the charges of complicity in the assassination attempt on Hokishe Sema in August.

[12] The incumbent Chief Minister Hokishe Sema refused to set up an enquiry committee to investigate the details that led to the arrest.

Jamir alleged that the confessional statement that led to his arrest was "prepared" by some interested officials "to meet their selfish end.

The central government headed by Vishwanath Pratap Singh had outlawed the NSCN along with United Liberation Front of Asom on 28 November 1990.

[2] In July 2009 he took additional charge of Gujarat state during the medical absence and subsequent death of Governor-designate Devendra Nath Dwivedi.

[7][23] During his tenure as Chief Minister, The Comptroller and Auditor General (CAG) unearthed a major financial scandal in the Nagaland state lottery amounting to Rs 38,297 crore.

Jamir denied his government's involvement in the financial scandal but the special audit by the Comptroller and Auditor General (CAG), ordered by the Union Home Ministry, indicted both the Nagaland Government and the state's sole distributor of tickets, M.S Associates, for defrauding the public as well as the exchequer of the amount in July 1999.

[27] In year 2020, Mr Jamir was conferred with the third highest civilian award--Padma Bhushan—in the field of public affairs on the occasion of 71st Republic day.