1968 - 1969
N.S.N. Children’s School was started at Chromepet.
1981 - 1982
Upgraded as N.S.N Matriculation School.
1985 - 1986
Upgraded as N.S.N Matriculation Higher Secondary School.
1993 - 1994
N.S.N School Celebrated its Silver Jubilee.
2010 - 2011
N.S.N. Scouts & Guides Movement celebrated its Silver Jubilee.
2012 – 2013
N.S.N. Memorial School, affiliated to CBSE, was started at Chitlapakkam.
2016 – 2017
N.S.N. Memorial School was upgraded to a Secondary School.
2017 – 2018
NSN Group of Schools received NABET Accreditation from the Quality Council of India, New Delhi.
2018 – 2019
N.S.N. School celebrated its Golden Jubilee and N.S.N. Memorial School was upgraded to Senior Secondary School.
March 8, 2025
NSN Memorial School inaugurated its new branch at Kundrathur.