[3] Sachin was born to K. M. Nandakumar and Sheeja at Nellikode in Kozhikode district of Kerala, India.

His mother is a teacher at Government Higher Secondary School, Medical College Campus, Kozhikode.

[citation needed] He started his political life as a member of Students Federation of India (SFI).

[citation needed] Sachin is a Kozhikode Town Area Committee member of CPI(M).

In 2021 Kerala Legislative Assembly election he won against Dharmajan Bolgatty at Balussery Constituency with a lead of 20,372 votes.