Both Google and Facebook have stopped support for each other now. This means you cannot find your Gmail contacts in Facebook the official way.
Enter Gmail Contacts, a Facebook app that finds which of your Gmail contacts are on Facebook and then gives you the option to friend them.
Finding your friends is a simple and quick process, just grant access to the app and then it will present you with a list of contacts (max 50 at a time) that you are not friends with on Facebook.
Next, simply click on the “Add now!” button to send a request to a contact you wish to add. As with the usual method, you can also send an additional personal message with the request.
The app uses Google’s API, so you don’t have to give out your password to it.
Another way to import your Gmail contacts is to visit this page and manually entering email ids.
Visit: Gmail Contacts