A comprehensive study is undertakenon the functional development of brain in Autism Spectrum Disorder (ASD).Brain functionality trajectories are unique in autism spectrum disorder .Autism spectrum disorder (ASD) is a set of neuro developmental disorders characterized by a deficit in social behaviors and nonverbal interactions such as reduced eye contact, facial expression, and body gestures in the early childhood days till the age of three. It is not necessarily a single disorder, and it is broadly considered to be a multiple disorder resulting from genetic and non-genetic parameters and their interpretation. Hereditary study of ASD has acknowledged mutations that interfere with typical neurodevelopment in womb through childhood. These DNA complexities of genes have been involved in synaptogenesis and axon motility. Recent developments in neuroimaging studies have proved many vital perceptions in vivo into the pathological changes which occur in the patients’ brain with ASD. Amygdala plays a majorrole in the limbic system and the affective loop of the cortico-striato-thalamo-cortical circuit, in cognition and ASD has been proved invarious neuropathological and neuroimaging research findings. Besides the amygdala, the nucleus accumbent is also considered as the vital ingredient which is related with the social recognition response in ASD. Although educational and behavioral treatments have been the mainstay of the management of ASD, pharmacological and interventional treatments have also shown remarkable benefits in subjects with ASD. Also, there have been implications on few patients who experienced through one of the interventional treatments resulted improvement after deep brain stimulation. The key architecture of ASD development which could be the focus for intervention is still an untapped destination. Further work is needed to explore the horizons on the grey trajectories on ASD.