On Wednesday night, Tekashi 6ix9ine was transferred from Brooklyn's Metropolitan Detention Center to a facility often used to house collaborating witnesses.

If the troll rapper -- who's facing six RICO and gun charges and life in prison -- is singing he better have a good tune because it looks like the Feds have the goods on him.

TMZ has obtained video of 6ix9ine seemingly ordering a hit on Chief Keef's cousin Tadoe. The conversation took place days before Chief Keef got shot at outside of his New York hotel.

"Matter fact, I'ma just get your address. I know where you at," 6ix9ine says at the end of his FaceTime with Tadoe. "You gonna be in your crib, or Sosa hotel?"

After he hung up, he addressed his crew:

"Yo, I gotta thirty pack on him right now," Tekashi tells his boys. "Swear to God I gotta thirty pack. Thirty thou cash."

6ix9ine has denied involvement in Keef's hotel shooting (the shooters missed.) But in light of that, this is pretty incriminating .