How to access static method inside controller ASP.Net MVC

Yes you can but you need to make a static class and access the static class inside the controller.

You can just put it in a class like below.

public static class Utilities
{
    public static string ReturnSomething()
    {
        // code here
    }
}

Then you can call it from any of your controllers, no matter what their base class is.

public ActionResult index()
{
    string test = Utilities.ReturnSomething();
}

Note that you should not generally be accessing your controllers from your view template. The controllers should pass data to the views and it should be a one-way flow of information from controllers to views.