The government said this in its counter affidavit in response to a petition by Nalini seeking premature release.
The case is expected to come up before Justice M Sathyanrayananon Monday.
Nalini submitted that she had spent quarter of a century in jail though the legal requirement was only 20 years to be eligible for premature release.
The Supreme Court had awarded death penalty to four of the 26 persons found guilty in the case, including Nalini and her husband Murugan. It awarded life to three others.
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The death penalty of the three others, Murugan, Santhan and Perarivalanwas commuted to life by the apex court on February 18, 2014 on the ground of inordinate delay in disposing of their mercy petitions by the President.
She referred to a 2011 Government Order which facilitated the release of life convicts who served 20-year jail term
Since the case was probed by a central agency, the state government is obliged to 'consult' the Centre in the case of premature release of convicts. The state government wrote to the Home Ministry on February 19,2014 seeking its views on the proposal to release all seven life convicts.
The Centre had moved the Supreme Court to quash Tamil Nadu government's proposal.
On Dec 2, 2015, the apex court ruled that the term 'consultation' in Sec 435(1) of CrPC implied 'concurrence'. Only after that did the state government seek a clarification from theCentre, which is still awaiting reply.
The counter said the three-member bench of the Supreme Court had on April 18, 2016 decided tohear the Centre's case every Monday and Friday and added that the case had so far not been listed for hearing.
Tamil Nadu government detailed all correspondence between the state and the Centre in the counter.