Blockchain is digital distributed decentralized Database. Blockchain distributed ledger system provides a tamper-resistant and decentralized framework for recording transactions. Blockchain removes the need of intermediaries in transactions, reduce the cost and improve the efficiency. In today era, blockchain is used almost all real-life based application for security purpose for example Smart home, healthcare, Smart city, Smart Supply chain Management. Moreover, it also improves the security and privacy of IoT data, as data added or updated through consensus algorithm among participants. So, Consensus algorithms contribute a significant role to ensure the security and efficiency of the blockchain. In the present study focus is on collaboration of blockchain in Smart Internet of things (IoT) and comparing the different types of consensus algorithm and time taken by various consensus algorithm for verification and adding block in blockchain.