Which southern state refused to ratify the Twenty-fourth Amendment?
Assuming you mean the state that rejected the 24th Amendment, the answer is Mississippi. However, South Carolina, Georgia, Arkansas, and Louisiana (all southern states) have not yet ratified it.
8 states have still not ratified the 24th Amendment, and among them is Mississippi - the only state to specifically reject it.
The other states which have not yet ratified the 24th Amendment are South Carolina, Georgia, Arkansas, Louisiana, Oklahoma, Arizona, and Wyoming.