New Mentor requirements

[Crushnight]

You are going to need:
-1,000 dungeons/raids/trials completed
-1,500 player commendations (A Huge increase from 300 ty for this any steeper requirements is better than current ones)
-1 tank lv80 and complete role questline
-1 healer lv80 and complete role questline
-1 DPS lv80 and complete 1 of the role questlines

That is the new requirements for Battle mentor submission whereas trade mentors requirements haven't changed since they announced them pre ShB.

EDIT: link https://na.finalfantasyxiv.com/lodes...024.1530816626

few extra things those that register as Trade Mentors won't have access to Mentor Roulette.
You need to re register as a mentor between Patch 5.1 launch and sometime in December 2019 under the new requirements.