A bench of justices T S Thakur and Gyan Sudha Misra said it cannot pass any direction as the convict has not filed any petition before it and the petitioner Abhinav Ramakrishna has no locus standi to plead on his behalf.
The apex court also allowed a NGO, Lawyers for Human Rights International, to withdraw its petition filed with a similar plea.
The bench told Abhinav Ramakrishna, an advocate, that since the petition was filed under Article 32, it cannot be entertained as no fundamental right of the petitioner had been violated.
In other words, the bench said, the provision of Article 32 could be invoked only by a person whose fundamental right has been violated.
The NGO had contended in its petition that Rajoana was not properly represented during the trial of the case and he had not filed any appeal in the Punjab and Haryana high court against his conviction and capital punishment.
The NGO was seeking a stay on the execution of Babbar Khalsa militant Rajoana's death penalty, which was slated for March 31 but has already been stayed by the Centre. Rajoana is presently lodged in the Patiala Central Jail.
The NGO had challenged the March 22 order of the Punjab and Haryana high court, which had dismissed a PIL against the lower court's order convicting Rajoana and awarding the death penalty to him.
It had said the decision in the case has not attained finality as the CBI has challenged in the apex court the commutation of death sentence to life term of co-accused Jagtar Singh Hawara.
"That it is submitted that the judgement by which the death sentence has been confirmed, is under appeal before the Supreme Court at the instance of the CBI. The special leave has been granted in an appeal against the conviction of Hawara. So the decision has not attained finality, therefore, the death sentence cannot be executed," the NGO had said in its petition.
Rajoana, a police constable and a close friend of another assassin Dilawar Singh Babbar, was the second human bomb to be used, in case the first one failed to kill Beant Singh on August 31, 1995.
The special CBI court had awarded death sentence to Rajoana and Jagtar Singh Hawara on August 1, 2007.
Other co-accused Lakhwinder Singh, Gurmeet Singh and Shamsher Singh were sentenced to life imprisonment for hatching a conspiracy to kill Beant Singh.
Rajoana did not appeal against the judgement.
The death penalty of Hawara, who filed an appeal against it, was later commuted to life term.