Every character on Jiǎoluò Shūwū read as xiao in any tone — 2 readings total across the four tones. Pick the tone you mean.
If you have the sound xiao but not the character, here are the 2 characters read this way: 小 (xiǎo, small, little; humble), 笑 (xiào, to laugh, to smile, to mock). They split across 2 tones, so the tone is what separates them.