Of the total 13 accused, nine directors and four employees, arrested on the charge of culpable homicide not amounting to murder, 12 have so far been given bail.
Three other directors of the hospital are absconding.
Only one official, Sajid Hussain, remains in custody.
A fire broke out in the basement of the hospital's seven-storey, centrally air-condition annexe building in the early hours of December nine.
More than 90 people, mostly patients, were suffocated to death from smoke that entered the floors through AC ducts.