Chettri began his footballing career in 2000 with Namchi Sports Hostel after being discovered in the Sikkim governments Search for More Bhaichung's campaign (In reference to then India striker and Sikkimese-born Baichung Bhutia).

[1] In 2002 Chettri played for Namchi in the Subroto Cup where he led the team to the final, only to lose to Mizoram 1–2.

[1] After good performances with Sikkim Chettri was scouted and signed for Air India FC of the I-League in 2007.

[1] He made his Asian debut in the AFC Cup in 2010 against Al-Ittihad Aleppo of Syria on 10 March.

[5] He made a dream debut in the green & maroon jersey scoring McDowell Mohun Bagan's opening goal in their 6–0 thrashing of West Bengal Police in the Calcutta Premier Division.

[7] On 12 May 2013 in the last match of the 2012-13 I-League, he was assisted by Denson Devadas on the 5th minute to score the 1st goal in the 3–0 victory over United Sikkim F.C.

[1] Chettri was then selected for the India U23 team that was selected to take part in the 2009 SAFF Championship which the India senior team choose not to play in SAFF Cup due to practice arrangements for the 2011 AFC Asian Cup.

[15] Chettri then proceeded to play in India's next 4 games in the tournament which ended with the Final against Afghanistan on 11 December 2011 at the Jawaharlal Nehru Stadium in New Delhi.

[16] The game ended 4–0 in India's favour, thus giving Chettri his first major honour with the senior national team.

His footballing education started at Namchi Sports Hostel, where he moved after getting selected in the Sikkim Government's ‘Search for more Bhaichungs’ campaign.