What is the best retirement age in the public service ?

if you are starting a business for yourself.

if you want to retire and spent your days traveling and exploring the world.

....... never retire if retirement to you is to set at home and do nothing cause you will fall in depression then

There isn't one.  It depends on the role, the individual and the wider context.

Fixed retirement ages are a silly idea.  Nobody benefits from them.

in  public  service best retirement is age