Can cockatiel and African grey get along if you put them in same cage there are at moment in separate cages the cage you have got is a macaw cage so it is big enough?

Small parrots don't do well with big ones, the African grey will become dominant, and it will act aggressively with the cockatiel. a cage is not a good idea no matter how big it is, only an aviary will be good enough to house them.