I haven't been following the 6ix9ine situations too close but I think it all goes back to his beef with Trippie Redd
Trippie did a song with Tadoe (and maybe Keef? IDK) and 6ix9ine was on IG calling Tadoe a bum and a has-been...even a never-been (which is true). Then by extension I think he called all of GBE bums and has-beens . I would guess they took offense to this and there was a little back and forth.
Keef had beef with gang members in NJ years ago but I don't think this is that. I think this is either industry theatrics or literally, treyway shyt