Hi UG
Well let's talk scripture. What does it mean to be "Under the Law"? So we can see if the "Gentiles are under the law" Here let me help you out ....
So what does it actually mean to be “Under the Law” and what does God’s Word say?
Rom 2:12-13
All who sin apart from the law will also perish apart from the law, and all who sin under the law will be judged by the law. For not the hearers of the law are just before God, but the doers of the law shall be justified." (Rom 2:12-13)
Rom 6:14
For sin shall not have dominion over you: for ye are not under the law, but under grace.
Rom 6:15
What then? Shall we sin, because we are not under the law, but under grace? God forbid.
Rom 6:16
Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?
Rom 6:17
But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you.
Rom 6:18
Being then made free from sin, ye became the servants of righteousness.
To be “Under the Law” means to be convicted of sin, to be guilty before God as a sinner. The sinner is under the Law because he has broken the Law and is guilty of breaking the God’s Law. This applies to both Jews and Gentiles believers because without God's Law is no knowledge of Sin
Hope this help
God Bless