There was a recent discussion on this, still at the bottom of this page.

I don't know enough about tandoors, but I've read they get to 600. Most of the chicken
I've had from local Indian restaurants has enough blackened areas to make me believe they are
doing the chicken at 600.

I've done tandoori chicken several times on my medium at 400, but run the heat up in the last 10
minutes. They turned out fine. Just a little blackened at the edges. The best were coated with an
imported tandoori paste, marinated 24 hours, and left with a good coating of the yoghurt paste mix
on when placed in the Egg.

Tandoori marinade also works well with rabbit. The marinade helps the meat be a little moister, and
perks up the fairly bland flavor.

I do tandoori chicken all the time...