How to create Plugin for Kibana 5.6.3

I want to create a plugin for kibana version 5.6.3, due to this I follow the link "https://github.com/elastic/kibana/blob/master/CONTRIBUTING.md#contributing-code", the GitHub provider the source code of the latest version kibana 7.0.0 https://github.com/elastic/kibana .but I need the kibana version 5.6.3 to create a plugin, where I get the source code

Hey @RajeshAJ if you're already cloned the github repo, you can run git checkout 5.6 to switch to the 5.6 branch.