Rehab post/amputatio. The rehab after an amputation it is always a benefit for the patient. You did not specified where (which part of the body) the amputation has been performed. And the rehabilitation must be specific for the part of the body affected.
Physical therapy. Immediately after am amputation training starts to insure the person can manage the home environment, mobility, and activity of daily living independently. After a prosthetic is received physical therapy is prescribed for prosthetic training. The duration of therapy depends on multiple factors including the health of the other leg, the exercise tolerance, and type of amputation.
Depends on site. This is completely variable on the site that was amputated. Talk to your surgeon if you have questions.