Potassium permanganate is a strong oxidizing agent. Permanganate is an intense dark purple color. Reduction of purple permanganate ion to the colorless manganese ion, the solution will turn from dark purple to a faint pink color at the equivalence point. No additional indicator is needed for this titration. The reduction of permanganate requires strong acidic conditions.
This video explains how to determine the concentration of potassium permanganate solution by titrating it against a standard solution of (a) Oxalic acid and (b) Ferrous ammonium sulphate (Mohr’s salt).