EXCLUSIVE

Three known associates of Tekashi 6ix9ine just got slapped with federal indictments, and law enforcement sources tell TMZ ... Tekashi dropped the dime on one of them for the Chief Keef shooting.

Law enforcement sources tell TMZ ... Kintea McKenzie, Anthony Ellison and Denard Butler have all been indicted in connection with crimes related to Tekashi.

More specifically, we're told McKenzie (aka Kooda B) was indicted right after Tekashi spoke with investigators and pinned him as the trigger man at the Keef shooting last June in Times Square.

McKenzie was allegedly paid $10k to shoot Chief Keef ... according to our law enforcement sources. Remember, Tekashi and Keef had been beefing leading up to the shooting. As we first reported ... 2 men, including a known Tekashi associate, tracked down Keef in NYC and opened fire but missed.

We're told authorities have not apprehended McKenzie. Ellison is already in custody for allegedly kidnapping and assaulting Tekashi ... and Butler was busted by the ATF on Wednesday. Ellison and Butler are expected to appear in court later this afternoon.

The U.S. Attorney's Office for the Southern District of NY declined to comment on Tekashi's cooperation. We've reached out to Tekashi's lawyer, so far no word back.