How to access Model sub classes in the view

Make the classes public

public class viewmodel(){
  public ClassA obj1 = new ClassA();
  public ClassB obj2 = new ClassB();
}

or the code below

public class viewmodel(){
   public ClassA obj1 {get;set;}
   public ClassB obj2 {get;set;}
   public viewmodel()
   {
      obj1 = new ClassA();
      obj2 = new ClassB();
   }
}