Sujata is a BA third year student at Vivekanand College of DU where she had gone to appear in examination, police said.
"She had her exam today. She fell down from third floor of the building which had no grill," said Rishi Pal, DCP (east).
The incident occurred around 12.45 pm and she was rushed to Max hospital in Patparganj, in a critical condition, he said.
Investigations so far led to suspicion that the girl had attempted to commit suicide, police said.