The city police contended that Nanda should be convicted under the stringent provision of Section 304 (2) of the Indian Penal Code (IPC), dealing with culpable homicide not amounting to murder.
The law prescribes 10 years imprisonment as maximum punishment.
In 2009, the trial court had convicted and sentenced Sanjeev Nanda to five years imprisonment.
Nanda, whose sentence was later reduced to two years by the Delhi High Court, is out of jail now after serving his term.
Besides Nanda, the court had also convicted Rajiv Gupta and Bhola Nath and sentenced them to one year and six months in jail, respectively for destruction of evidence.
Nanda had mowed down seven people, including three policemen, while drunk and driving his BMW car. Six persons died on the spot, while one survived.