EXCLUSIVE

Tekashi69 is unfazed by the feds' collection of photos and videos, allegedly tying him to multiple crimes, and insists he's in no mood to play "Let's Make a Deal" ... TMZ has learned.

We broke the story ... prosecutors submitted a stack of images to the judge, just to make the point that Tekashi needs to remain behind bars until his trial begins ... in September. The evidence seems pretty damning, but 6ix9ine's attorney says they're not flinching.

Lance Lazzaro tells us, "A plea deal is simply off the table, even if the feds offer one." He says they're prepared to go trial and prove Tekashi's innocence.

As we reported, prosecutors have pics and videos linking Tekashi and his crew, including Kifano "Shotti" Jordan, to at least 3 armed robberies and/or shootings in Brooklyn earlier this year.

It's true, none of the images show the rapper pulling a trigger, or even holding a weapon -- but the feds are alleging he was the mastermind behind the crimes, even if he didn't do the dirty work.