Hi! My father of age 50, is suffering from Left side Paralysis for the past 11 years also his speaking capacity also gone. We have undergone almost all treatments like allopathy,phisiotherapy, naturopathy,.... we cannot find a solution to cure him. It would be much helpfull if you give an exact way to cure his disease.
Unfortunately the body itself is the best and only healing and restorative process we have despite all if our medicine.  It depends on the type of damage that caused the symptoms but in most cases the latest a person will continue to see recovery is 1-2 years. At 11 years there is likely little left that can be done to restore function. Talk to your neurologist about the prognosis for return of function as there is not enough information provided here to help. You and your family should focus on other ways to help him communicate and mobilize.