Sivakumar was the former agriculture minister and speaker of the union territory of Puducherry.
His family had dominated the constituency of Neravy T.R.Pattinam for decades by winning about 10 elections.
He was murdered by armed gang due to personal enmity in 2017 January.
The reason was said to be the personal enmity between Sivakumar and a liquor baron Ramu's family.
Days later, it was found Ramu's second wife Ezhilarasi's role was behind the murder.