K. N. Nehru was born in Kanakilliyanallur on November 9, 1952. He completed his school education and now lives in Trichy. His son K.N Arun Nehru is also actively working in Trichy DMK.^[2] Nehru has three brothers and one sister.

Nehru's father is an Indian National Congress member that is why he named his son as Nehru. Later in the early 1970s his family moved to Dravida Munnetra Kazhagam.Started his political career as pullambadi union chairman.

In 2021 under his leadership Secular Progressive Alliance won all the 9 seats in Tiruchirappalli district.

Nehru successfully organized many high level party meetings were more than lakhs of DMK cadres come to participate, So the DMK party leader and tamilnadu chief Minister M. K. Stalin always praises Nehru as "Maanadu endraal Nehru, Nehru endraal Maanadu".

Nehru has been elected to the Tamil Nadu Legislative Assembly on four occasions, twice from Lalgudi constituency, in the elections of 1989 and 1996^[3] and thrice from 2006, 2016 and 2021 Tiruchirappalli West constituency.

Nehru was the Minister for Transport in the DMK government from 2006 to 2011. During this period, the bus fleet was modernised and improvements were made to the frequency of buses, passenger amenities and connections to the new suburban areas of Chennai.^[4] More than 10,000 new buses were introduced across the state.^[5][6] Fuel efficiency was given an important thrust and drivers were educated on importance of managing fuel.^[7]

Cases have been filed on Nehru by the All India Anna Dravida Munnetra Kazhagam government but the courts have dismissed them as being vague.

The Madras High Court struck down the controversial land-grabbing cells which were primarily used to torment common people and opposition figures. The court had clearly remarked chance of misuse by officials and ruling government citing broad language used in the act.^[8]