In recent times Internet of Things (IoT) has gained popularity because of its characteristics in connecting and providing communication among various physical objects and devices enabling collection of diverse data that help making smart and educated decisions which in turn help making human life simple, safe and efficient. Traditional Wireless Sensor Networks (WSNs) are now becoming mainstream data source for IoT applications by connecting to uniquely addressable and routable gateways. Wireless Sensor Networks are defined as a collection of devices with limited resources like processing, memory, power and bandwidth, deployed for sensing various scalar and multimedia data with diverse traffic types. These data are critical and has to reach the sink in time. The constrained nature of the network with inherent approach of best effort data delivery, not only imposes challenges in reliable transmission of data but also the real time delivery of the data. With increasing use of IoT technology in Smart solutions such as Access control, Real time inventory, Flow optimization, one of the key problems of next generation WSNs is the real-time management and control of network paths within the sensor network so that mission critical data from sensor nodes reaches the IoT Gateway in real-time. In addition, given the myriad type of applications in WSN, imposes the need to segregate and treat data traffic variedly based on the criticality of the application and/or data. Hence there is a need to address the aspects of optimal usage of resources for handling delivery of critical data satisfying its Quality of Service (QoS) requirements within the sensor network. This paper proposes optimal resource reservation mechanism which has resulted in optimal utilization of resources by allocating sufficient resources for prominent and critical data and hence reducing the delay and increasing the performance of the system.