I need the detailed steps to access the application from another network if i have kept this application on windows server OS
You need to contact a network administrator / consultant. As that is a simple general computing task for someone with network knowledge.
The alternative is to use the cloud version as Lubos will then do that and several other network administration tasks for you
Or develop the skill yourself. You will need the support of a general computing forum. For the small Manager specific part and an overview see the Guide
Self-Hosting: Self-host a Manager installation
In particular this link it contains https://www.manager.io/server/installation/windows/