Helo sir, iam Sivakumar I age 29 average height...

how can you get taller ?
unfortunately there is no nay way to get taller but with surgical means at this age and its done using an ilizarov technique ( the doctor will fracture your leg bones the he will apply the ilizarov device and then the bones are healed but with the force of screws that extends the length of the portion of the healing bone ) 
what are the diagnosis of short stature in age above 21 years old ?
the clinical examination and the medical history are the only investigation required
what are the causes of short stature ?

• family history  of short stature 
• a presentation of a chronic illness during childhood ( such as malnutrition ) 

what is the advice ?
in such cases we  advice you to visit an orthopedic that is an expert in such surgeries and is familiar with this device to make you taller