Does the Sig 7.62 Titanium suppressor come with a assembly?

I think it depends on who you buy it from. Since the brake/mount is usually $100 or more a lot of companies sell them separately so they can lower the listed price of the suppressor. They should usually say though, and usually will ask you to select a thread pattern if they are including one.

The Sig QD suppressors are supposed to come with a brake. They sell brakes / flash hiders separately so that if you have multiple rifles, you can have a suppressor mount on each rifle without having to take the muzzle device off (which would be a horrific PITA).

when i ordered my sig 7.62tiqd they only had the brake out and that is what came with my suppressor, (typically you specify which one you want when ordering)upon picking it up they had the flash hiders so i picked one of them up for my 6.8 $60 not bad. ps i love the sig suppressor my 6.8 sounds like a powerful air rifle with full power hunting loads!