@lokeshpokar, this thread is located on the Olsen Light support page, and so the questions here have to do with that theme. You are running a different theme, which is why the CSS isn’t working for you, i.e., while there are some standard WordPress classes and IDs, most themes use different classes & IDs for their elements.
On your site, I do not see any other menu other than the one which comes with the theme. However, if you still want to hide the menu on the home page, you would go to Appearance → Customize → Additional CSS and copy & paste in this rule:
.home .site-header .main-navigation {
display: none !important;
}
In the future, please start a new thread instead of jumping into an existing one. That way the original poster won’t get unrelated emails that they are not interested in.
Thanks.