Every character on Jiǎoluò Shūwū read as dian in any tone — 2 readings total across the four tones. Pick the tone you mean.
If you have the sound dian but not the character, here are the 2 characters read this way: 点 (diǎn, dot, point, a little, o'clock), 电 (diàn, electricity, electric, telegram). They split across 2 tones, so the tone is what separates them.