Lajong finished the final round at the top of the table and hence gaining promotion to the 2011-12 I-League.
Boithang's season got off to a good start as he scored for Lajong in the 2011 Federation Cup against Churchill Brothers in the 70th minute on 17 September 2011.
[2] He would score his first goal of the 2011-12 season against Chirag United Kerala on 24 March 2012 in a 3-2 loss for his team.
Boithang established himself as a first team regular at Lajong during the 2012-13 I-League season, appearing 22 times and scoring 4 goals.
[4] Boithang represented NorthEast United FC during the 2014 Indian Super League.