The use of blockchain technology into the Internet of Things (IoT) presents a number of major benefits, including enhanced data integrity, decentralised trust, and security against unauthorised access. Traditional implementations of blockchain technology, on the other hand, encounter difficulties in terms of scalability, latency, and resource limits, all of which are particularly important considerations in Internet of Things scenarios. The Internet of Things (IoT) networks are proposed to be improved in terms of security, scalability, and efficiency by the use of a layered blockchain architecture. In order to optimise the processing of transactions and the storage of data, the suggested framework makes use of a hierarchical structure. This structure allows lightweight Internet of Things devices to connect with blockchain layers that are situated on the edge and the cloud. Permissioned blockchains for local Internet of Things clusters and interoperable mainchain solutions are incorporated into the concept, which allows for a reduction in computational cost while simultaneously retaining security. Moreover, the optimisation of smart contracts, upgrades to cryptography, and consensus procedures that are specifically designed for devices with limited resources guarantee that actions are carried out efficiently. A strong blockchain-based Internet of Things architecture that is appropriate for large-scale deployments is offered as a result of this study, which tackles technological difficulties such as reducing latency, increasing energy efficiency, and enhancing interoperability.