Iron oxide, or rust, is what makes soil red. There is more than one type of red soil. All are clay-rich but some are high in silica. What is the texture of yours? Is it heavy, fine and does it drain poorly?

When I lived in southern Indiana, the soils were as red as red can be and very heavy in clay. All needed to be amended to the hilt for strong plant growth--especially when it came to growing non-native bedding and vegetable plants. Red soil is found below the surface layer of more fertile, organic soil so it generally lacks organic matter.

My guess is that your soil would not be suitable for potting soil. Potted plants grow best in organic-based potting mixes. Larger pots with more perminent plantings may contain highly amended earth, but in these cases it's better to start with a relatively fertile loam, not clay-rich earth.