The problem is the way you are growing the mysore raspberry: free form. If you train them on a wire, fence, or espalier, then that keeps the long canes from touching the soil and rooting, and it will not become invasive. This plant, unlike blackberry does not spread from the roots, so it can be easily controlled. The berries are pretty good, not the very best of raspberries, but if you live in a tropical climate then they are worth growing, as they are one of the few that will fruit in the tropics.