In this case your maximum IRA contribution is $6,000, the lesser of the $6,000 annual limit for someone under age 59½ in 2019 or the amount that will appear in box 1 of your W-2, $10,000.
Had your $7,000 of 401(k) contributions been to the traditional account in the 401(k) instead of to the Roth account, the amount that would appear in box 1 of your W-2 would be $3,000 and your maximum IRA contribution (assuming no compensation from another employer) would be $3,000.
