The Chief Minister of Tamil Nadu, J. Jayalalitha, recently stated that she does not have the power to commute the death sentences on three people for their alleged roles in the assassination of former Premier Rajiv Gandhi.

Technically, it is the Governor of Tamil Nadu who has this power. But the Tamil Nadu council of ministers can so advice the Governor. 

On April 25, 2000, then Governor, Fathima Beevi, ordered the commutation to life of the death sentence given to Nalini, also in the Rajiv Gandhi case. (She rejected the mercy petitions of the other three.)

It was the advice of the Tamil Nadu government that formed the legal basis for her decision.

See the Madras High court document here. Para 3 states:

“Mrs. Nalini made an application for clemency to the Governor of Tamil Nadu and same was rejected by the Governor of Tamil Nadu. Challenging the said order, Mrs. Nalini filed a writ petition before [Madras High Court]. [On] 25.11.1999, this Court set aside the order of the Governor and remanded the matter back for fresh consideration.

“Thereafter, the Council of Ministers, Government of Tamil Nadu, advised the Governor to commute the death sentence of Mrs. Nalini into one of life imprisonment. On accepting the said advice of the Council of Ministers, the Governor of Tamil Nadu commuted the death sentence into one of life imprisonment [on] 24.04.2000. And from 25.04.2000 onwards, Mrs.Nalini was converted as a life convict and she has been continuously lodged in the Special Prison for Women at Vellore.”

According to Chief Minister Jayalalitha, "The Central government has made it clear that the state government cannot ask the Governor to consider any mercy petition after the President of India has rejected it."

The President, Smt. Pratibha Devisingh Patil, rejected the mercy pleas of the other three in early August.

On Monday, the three moved the Madras high court challenging the rejection of their clemency pleas by the President. (See report by Times of India here)