## 1 Introduction
The cluster node reduces power wastage while transmitting and receiving the data. Finally, the data is forwarded to the gateway node to reach the internet server point. The gateway node is connected to a cloud network and the cloud system collects the data and stores the details. The following conditions are considered in the research:  
1. Cluster Network: More than one sensor node is connected as a cluster in the MANET. Each cluster is connected through a selected cluster head. 2. Routing Protocol: MANET considers an optimized routing protocol to determine the shortest route between sensors to the gateway node. 3. Internet and IoT: Data collected from various nodes are stored in the internet cloud server. The IoT is a recent technology widely applied in this electronic world. Generally, the open wireless medium has poor security and utilizes more energy to sense the data and transmit the data to the nearest gateway. The recent works developed for wireless data communication use secure internet protocol functions and transport layer functions. In this network, neighbouring sensor nodes are formed into a small group by one MANET node is called a cluster network. In the cluster, MANET nodes act as cluster heads (CH) to forward the information between sensors. This cluster formation is reducing the bandwidth utilization rate and increasing the sensor node's lifespan. In addition, MANET is creating a trusted route and shortest route between sensors in the Internet Cloud. Generally, clusters are created in MANET to easily organise the topology. In this manner, recent techniques use various energy-efficient clustering approaches for improving the performance of routing protocol. On the scope, clustering algorithms such as Low Energy Adaptive Clustered Hierarchy (LEACH) is a well-known algorithm for choosing the cluster heads based on optimal energy constraints. LEACH is a cluster formation protocol in a tree-based (hierarchical) network environment. Notably, the clusters of mobile nodes or sensor nodes are formed under the base station (centralized control centre). Clusters of nodes under each base station provide hierarchical network architecture. The IoT environment of cluster nodes can communicate with other cluster nodes through a centralized base station (control unit). In this case, cluster heads (nodes with the highest residual energy) can reach the base station for communicating the data [8]. In the same manner, real-time challenges and flat architectures in making MANET clusters are significantly noted by various research works. Unlike hierarchical IoT structures, flat network clusters can be formed for the distributed scenario. Particularly, flat networks deploy multiple gateway nodes for collecting the field node's data through cluster heads. The chosen gateway nodes are deployed in each cluster. In this method, cluster heads and other cluster nodes that are nearer to gateway nodes of neighbour clusters can communicate with each other. This kind of mechanism reduces energy overhead happens in each cluster head. Thus, the effective formation of clusters creates a crucial impact on energy-efficient data communication in IoT environments (hierarchical and flat networks) [9]. In this article, the MANET-ESO performance in the IoT environment is experimented with using the modules such as clustering principles, MANET-based on-demand routing process, IoT data collection process and trusted route establishment policies. The simulation environment is created by MANET mobile nodes and Wireless sensor nodes with Internet (cloud network). The Sensor nodes are divided into small clusters and grouped by Mobile Ad-hoc nodes. Upon the validation of energy levels, nodes are assigned as CH to control sensor nodes. The routes are discovered from the sensor source to the gateway node with the help of the MANET cluster and on-demand routing protocol. The best route is evaluated by the total energy of the route, time is taken from source to destination and minimum hop count.