A division bench comprising Justices Manmohan and Sangita Dhingra Sehgal, after admitting the plea, sought response from Ansari and other accused in the case.
Alka Rai, wife of the murdered BJP leader, had approached the high court against the trial court verdict acquitting Ansari and other accused in the case.
The matter will now be heard on November 28.
A special CBI court presided by Judge Arun Bhardwaj had earlier this year acquitted the accused in this "gruesome" case of murder of Rai and six others after all the eyewitnesses and other material witnesses turned hostile.
The court had then also slammed the probe agency, saying: "The case was another example of prosecution failing due to hostile witnesses. If the witnesses in this case had the benefit of Witness Protection Scheme, 2018 during trial, the result may have been different."
Rai was gunned down in Ghazipur on November 29, 2005 along with the others. The investigation of the case was transferred from UP Police to the Central Bureau of Investigation, and in 2013, the Supreme Court also transferred the trial from the state to Delhi on the plea of Alka Rai.
Ansari, who faces several cases against him including of murder and kidnapping, is currently lodged in Lucknow jail.
( With inputs from IANS )