What exactly is a rupture in the Achilles tendon, how is it treated, & what is the treatment time? Is there any kind of physical activity I can do?

Depends how your. ruptured it, and what recommendations your orthopedic surgeon has on the extent of rupture, type of repair needed. Since it involved weight bearing, the recovery will depend on what else is also injured along with this, and not adding more to it. Let your doctor dictate what activity you can do, or not do, so you can have full recovery. It may take a few months to heal,along with physical therapy.