Hi Kalikumar,
 

Let's say that you create your login page in the module Login.

The new page that you created has the different elements on it from the widget menu under the header:

Then your form should look something like this:

In the Login module add a module role Guest, and set the permissions for the new login form (above) to hte new Guest module role.

In the security settings make sure to create a user role: Guest and add the Guest module role from the Login moduel to this user role.

Under the Anonymous users tab make sure the anonymous users are enabled and the role is set to Guest:

In the navigation add the LoginForm as role-based-home-page for the user role Guest:

Keep the default home page as the page where the user needs to go after login.

Now when you access the url of your app you are an anonymous user and therefore the role-based-home-page is shown: The newly created LoginForm from the Login module. After entering the correct credentials and signing in you are redirected to the default home page. 

If needed you can setup more role-based-home-pages, so that when e.g. an Admin logs in the user is redirected to the Admin home page and other users are redirected to the default home page.

I hope this explains how to create your custom login page correctly.