Severe mental retardation is
Mental retardation level IQ range Mild 50-69 Moderate 35-49 Severe 20-34 Profound < 20 (Ref: A sho textbook of psychiatry, Niraj Ahuja,7th edition, pg no 156)
50 - 69
35 - 49
20 - 34
Less than 20
Child psychiatry