The victim, identified as Shadab Khan, is pursuing a diploma in management from a private institute in Nehru Park and lives with his family at Batla House area, said a police official.
The incident occurred around 1 am today when Shadab was walking in a pavement close to his home, while talking over his mobile phone, when the bike-borne snatchers approached from behind.
When Shadab resisted, one of them pulled out a gun and allegedly fired at him twice, said the official.
While one of the bullets hit Shadab's chest, the other brushed past his arm. Locals called up the police control room and Shadab was rushed to a hospital. His condition is stated to be critical, said the police official.
Police have obtained CCTV grabs from the area and are trying to ascertain the identity of the accused, who were wearing helmets. A case has been registered and investigation is underway, the official added.