조타 is a bad spelling of 좋다 (good), which is pronounced as [조타] when spoken. It's a case of spelling and pronunciation diverging as happens in most languages. There are numerous such instances, like 싫다 [실타], 맞다 [마따], 먹었다 [머거땨], etc. But spelling it like 조타 is not accepted by the language standard, and no one with serious intention will do it.

조타 = 좋다 which means It's good/ I like it/ Lovely ...etc It literally means GOOD! and is a chatting word! :-)