Which range of IQ is classified as profound intellectual disability?

NCERT (2025-26): “Intellectual Deficiency … The different levels of intellectual disability are: mild (IQs 55 to approximately 70), moderate (IQs 35–40 to approximately 50– 55), severe (IQs 20–25 to approximately 35–40), and profound (IQs below 20–25). Although the development of people with mild disability is typically slower than that of their peers, they can function quite independently, hold jobs and families. As the level of disability increases, the difficulties are strongly marked. The people with moderate disability lag behind their peers in language and motor skills. They can be trained in self-care skills, and simple social and communication skills. They need to have moderate degree of supervision in everyday tasks. Individuals with profound and severe disability are incapable of managing life and need constant care for their entire lives.…”