Nirmalanathan is president of the Vavuniya Citizens Committee.[2]

Nirmalanathan contested the 2013 provincial council election one of the Tamil National Alliance’s (TNA) candidates in Mannar District but failed to get elected to the Northern Provincial Council after coming fourth amongst the TNA candidates.[3] He was one of the TNA candidates in Vanni District at the 2015 parliamentary election. He was elected and entered Parliament.[4][5][6][7][8]

 
2.^ Thambiah, Mirudhula (25 August 2015). “Tamils in N-E and plantations A paradigm shift in voting patterns”. Ceylon Today.
3.^a b “Provincial Council Elections 2013 Preferential votes”. Daily News (Sri Lanka). 24 September 2013. Archived from the original on 2013-12-10.
4.^ “PART I : SECTION (I) — GENERAL Government Notifications PARLIAMENTARY ELECTIONS ACT, No. 1 OF 1981” (PDF). The Gazette of the Democratic Socialist Republic of Sri Lanka Extraordinary. 1928/03. 19 August 2015.[permanent dead link] 5.^ “Ranil tops with over 500,000 votes in Colombo”. The Daily Mirror (Sri Lanka). 19 August 2015.
6.^ “Preferential Votes”. Daily News (Sri Lanka). 19 August 2015.[permanent dead link] 7.^ “PM Ranil receives highest Preferential votes with 500,566”. hirunews.lk. 18 August 2015. Retrieved 19 August 2015.
8.^ “Preferential votes- General Election 2015”. adaderana.lk. 18 August 2015. Retrieved 19 August 2015.
9.^ Jayakody, Pradeep (28 August 2015). “The Comparison of Preferential Votes in 2015 & 2010”. The Daily Mirror (Sri Lanka).