Every character on Jiǎoluò Shūwū read as gao in any tone — 2 readings total across the four tones. Pick the tone you mean.
If you have the sound gao but not the character, here are the 2 characters read this way: 高 (gāo, tall; high; elevated; surname), 告 (gào, to tell, to announce, to report). They split across 2 tones, so the tone is what separates them.