Sign in to Gmail on your iPhone to use email, check out information, send and receive mail.
Gmail for iOS availability may depend on which country you’re currently living for and requires iOS 8.0 or higher.
Try adding your gmail account using built-in email app on iOS if your device is not compatible or not available in your region
This tutorial shows you how to do this on an iPhone, but the steps are identical on iPad.
Built-in email app on iOS
STEP 1: Go to Settings > Mail, Contacts, Calendars > Add Account
STEP 2 : Select “Google ™“. Then enter your Gmail email address, password and account’s description.
STEP 3: Select what data if you want to sync with Gmail (your email, contacts, calendars, and reminders). And tap “Save”
Gmail for iOS
Download or update the latest version of Gmail App
On your iPhone or iPad, open the Gmail app
Tap Manage accounts and then Add account.
Enter your Gmail username and password.
After your account is added, you’ll be signed in to Gmail any time you open the Gmail app.