I have 4 VMs for splunk index peering setup, out of which i will use 1 vm for Splunk License manage, 1 for search head and rest of two as a Index server.
When I try to configure Peer node , it asks for maser URl, do I have to make one of the index server as maser node then only I can configure peer node or is there any was to configure peer nodes without master node?
The term peer node is Indexer cluster specific. You need a cluster master node (first) to configure an indexer cluster. Assuming you just want the other two VM to be Indexers, a Splunk Enterprise instance is already an Indexer when installed (and a Search Head too). Just follow instructions from below link to set it as Standalone Indexer in distributed indexer. It lists all the configuration that you need to do in Indexer, forwarder and search head.