The proposed E-Business platform provides an online B2B Interaction System for SMEs in retail sector across Mumbai suburban area to operate their everyday business effectively. The proposed E-Business platform helps retail business owners to maintain inventory level normal at any situation like low or high demand situations with respect to time, retail space and finance management. It also provides record keeping, tracking of transactions, payments and consignments. Contextual Enquiry was conducted with business owners in Crawford Market Mumbai area. Sample users were selected from five different business categories to get a good understanding of various business processes. After analysis, insights were drawn from this study to make the design brief. The final concept e-Karobar is an online application where the retail business owners can manage their everyday business by using Mobile Devices (Tablets)/PC. This allows business owners to control fixed inventory levels, keep supply chain well maintained accordingly business needs. Business men can update product information by price tag, specifications, physical location with visuals of real products and also at the same time keep track on movements of consignments, payments, transactions. It generates different business reports to help business men in making various business decisions effectively.