What is recovery time for a year old torn rotator cuff and what might prognosis be for future? will this cause a disability in right arm?

Depends: Surgical recovery can take 3 to 12 months for full recovery depending on the tear size and extent of surgery. This should not cause disability once it is healed

Variable: Some additional info would be helpful: did you have an MRI? If so, is the tear complete or partial? Is it the supraspinitus tendon only? Have you seen a Physical Therapist? Is there any loss of mobility due to "capsulitis"? Finally, have you had surgery or not? If you had surgery for a significant tear of the supraspinitus tendon without other issues expect a recovery of 6-12 weeks. More info?