Access Website Hosted in IIS through LAN in ASP.Net

I've been asked to create a school management system and it should work without an internet connection on the client side.

The client specified that they have a LAN setup at their side and does not want something that has to be installed on each and every system so I believe it would be accessed through the browser.

So I would like to know the process of making the application and its database work on client side without internet. There will be multiple users who will use the application.

One more question, because the application doesn't require internet would an asp website be okay for this project?

Database: MS SQL

Thank you!