This paper attempted an experimental investigation on geotechnical properties of soft clayey layer collected from different locations of Tripura (NE state India) along with assessment of microstructural and mineralogical arrangements with an aim to characterize the soft clay deposits available in Tripura. River sedimented alluvial formations consisting of such soft clayey layer at shallow to moderate depths were mainly observed at various urban agglomeration situated at near river basins of the state. This softer clayey layer was found to be problematic from the view point of construction. Both disturbed and undisturbed samples were collected from various locations and undergone laboratory testing to evaluate physical and engineering parameters. Besides, scanning electron microscopy (SEM) and electron dispersive microscopy (EDS) investigation were performed to evaluate their microstructural and mineralogical composition. Finally, a database is prepared highlighting their physical and engineering behaviour for the ease of designers which may help to design the foundation or selection of ground improvement methods.