NET

21 To those free from the law I became like one free from the law (though I am not free from God’s law but under the law of Christ) to gain those free from the law.

Darby

21 to those without law^D8287, as without law, (not as without law to God, but as legitimately^D8288 subject to Christ,) in order that I might gain [those] without law.

Darby Bible Notes

law - Anomos, 'without law'. This is important as showing the true force of the Greek word anomia employed elsewhere, as in 1John 3.4, 'sin is lawlessness,' not 'transgression of law.' legitimately - Or, 'under law to Christ' (not under the law), i.e. rightfully, duly, subject to Him. I have said 'legitimately' to preserve the connection with law. See Acts 19.39, 'regular,' i.e. lawful and right.

KJV

21 To them that are without law, as without law, (being not without law to God, but under the law to Christ,) that I might gain them that are without law.

Strong's

21 To them that are without law^G459, as^G5613 without law^G459 ,(being^G5607 not^G3361 without law^G459 to God^G2316, but^G235 under the law^G1772 to Christ^G5547,) that^G2443 I might gain^G2770 them that are without law^G459.