The deceased include family head Rajendra's wife Laado and her first and third sons - Kamal, Parvesh as well as their daughter Himanshi; Kamal's wife Ashu and three daughters; fourth son Anil's wife and daughter Deepika.
Nearly 30 fire tenders were rushed to the spot to douse the blaze and carry out rescue operations.
Nine of a family died in the fire that broke out in a multi-storey residential building near Shri Ram Chowk, close to the Palam Metro station in southwest Delhi on Wednesday morning.
Three of those trapped in the fire - Anil (32), fifth son Sachin (29) and two-year old Mitali -jumped off for safety and were injured.
The five-storey building had a cloth and cosmetic showroom on the ground and first floor, while the family of the owner of the showroom, Rajender Kashyap, lived on the second and third floors.
While Pravesh was aged 33, Kamal was 39, Ashu 35, Lado 70, Himanshi 22, Deepika 28 and three minor girls were 15, six and three, according to a PTI news agency report.
Those injured being treated for 25 per cent burn injuries at Safdarjung Hospital.
Visuals from the scene showed thick plumes of black smoke billowing out of the building and rising into the sky, with flames engulfing parts of the structure as firefighters battled the blaze in the congested market area.
Firefighters carried out intensive search and rescue operations, making their way through narrow lanes and smoke-filled interiors to evacuate those trapped inside. The fire has since been doused, PTI quoted officials as saying.
The area has been cordoned off and a forensic team has been called to inspect the spot. The exact cause of the fire is yet to be ascertained. Further investigation is underway, police said.