Abstract: A system for classifying an activity and connectivity of a brain into at least one neuropsychiatric disorder from magnetic resonance imaging (MRI) images. The system includes an imaging device, a network, and a brain activity analyzing server. The system (i) generate a three-dimensional (3D) structural MRI image and a 4D functional MRI images of the brain, (ii) extracts one or more features associated with one or more regions of the brain using a parcellation scheme, (iii) analyses, using a machine learning model, an intensity of at least one voxel in the one or more regions, and (iv) classifies the activity and the connectivity of the brain into at least one neuro-psychiatric disorder based on a percentage of variation of intensity of the at least one voxel in the one or more regions of the brain over the one or more features from a predefined threshold value.