Born in Meghalaya, Nongrum joined Shillong Lajong as a youth player in 2010. While with Lajong, Nongrum participated in the Subroto Cup with his high school team, Myngken Christian HSS. He eventually made it up to the under-19 team where he played for the club in the I-League U19. He scored a brace for Lajong in the game that clinched the title for his club against Langsning on 29 November 2014.
His performance for the club in the Shillong Premier League earned Nongrum a promotion to the first-team
He made his senior debut for the club on 14 February 2015 in the I-League against Bengaluru Football Club. He started the match but could not prevent Shillong Lajong losing 2–0. Nongrum was called up to the India U19 side in 2013.