I am sorry to learn that your mother has developed tuberculosis, which occurs 10 to 15 times higher in patients with kidney transplants. Most patients will respond to treatment and this condition should not be life-threatening if diagnosed early as appears to be in your mothers case. Mostly, its re-activation of the inactive tuberculosis which most Indians have by 15-20 years of age. The treatment has to be continued for 18 months as Rifampicin is usually not used because of its interaction with cyclosporin (immuno-suppressant used in transplant patients). Your mother should start to feel better in 2-3 weeks time.