Premature retirement

My only son has joined Indian airforce in 2011 as an airmen. He has completed 11 years and still in service. He is my only son. Me and wife are senior citizens and suffering from old age ailments like hypertension, polycystic kidney disorder (wife only). My son is also blessed with a baby boy in 2021. But due to our medical condition he is forced to keep his family at home to look after me and my wife. With the progress of time our age is also increasing. Many times he don't get leave to come home at the time of requirement, this further adds to our problem. I asked my so to apply for posting to home town. But, posting is also seems impossible because, the system on which he is trained is not available in our hometown. We are also not in position to move with our son as we have our property to look after and can't leave it unattended. Soon he is going to complete 15 years of service. We want him either to come home posting for last 5 years or apply for premature withdrawal from service. Is there anything which can be done.