@Gaurav JainIdeally load-balancing would be handle by the systems pushing data to your NiFI. When that is not possible and you are forced to ingest all data to a single Node in your NiFi cluster, load-balancing must be handled via a dataflow implementation.
Using a Remote Process Group (RPG) is the most common solution used to redistribute already ingested data across all node sin a cluster, but you can also use multiple PostHTTP processors (1 for every node in your cluster) and a single ListenHTTP processor to build a FlowFile distribution dataflow.
See the following for more info...
https://community.hortonworks.com/articles/16120/how-do-i-distribute-data-across-a-nifi-cluster.html
Thanks,
Matt