I've shared similar information before but perhaps it bears repeating. A simple internet search and here is what I found about these four popular translations.
NIV - A 15-person team including men and women University and Theological professors from the US, Great Britain, Canada, Australia, and India. https://www.biblica.com/niv-bible/niv-bible-translators/
NRSV - The ecumenical NRSV Bible Translation Committee consists of thirty men and women who are among the top scholars in America today. They come from Protestant denominations, the Roman Catholic church, and the Greek Orthodox Church. The committee also includes a Jewish scholar. https://www.biblegateway.com/versions/New-Revised-Standard-Version-NRSV-Bible/
NLT - A 93-person team of Bible scholars and stylists involved in this work are Christians who accept the Bible as the inspired Word of God. Most of the translators are professors in seminaries or universities. https://www.tyndale.com/about-the-nlt and https://wpmu.azurewebsites.net/nlt/meet-the-team/
NKJV - A 130-person team, including Greek, Hebrew, and English scholars, editors, church leaders, and Christian laity, was commissioned to work on the project. https://www.thomasnelsonbibles.com/nkjv/scholar-team/NIV - A 15-person team including men and women University and Theological professors from the US, Great Britain, Canada, Australia, and India. https://www.biblica.com/niv-bible/niv-bible-translators/
NRSV - The ecumenical NRSV Bible Translation Committee consists of thirty men and women who are among the top scholars in America today. They come from Protestant denominations, the Roman Catholic church, and the Greek Orthodox Church. The committee also includes a Jewish scholar. https://www.biblegateway.com/versions/New-Revised-Standard-Version-NRSV-Bible/
NLT - A 93-person team of Bible scholars and stylists involved in this work are Christians who accept the Bible as the inspired Word of God. Most of the translators are professors in seminaries or universities. https://www.tyndale.com/about-the-nlt and https://wpmu.azurewebsites.net/nlt/meet-the-team/