How do i play or unlock anneversery ffa bbt squad

How do i play or unlock anneversery ffa squad or bob in halo reach

What do you mean?
The BOBS are special Elites, usually a Golden Ranger, but a few missions have a random-class generated BOB wielding two Plasma Rifles. They can only be found on Heroic or Legendary and have different spawn locations. There’s a BOB in every mission.
However, Tip of the Spear is a weird case. It doesn’t always spawn and when it does, it’s usually a glitch. I remember encountering a BOB during a regular gameplay. I died, but it didn’t appear again for the entire mission.
As for “ffa squad”, I don’t know what you mean.