How long does it take a man to be reborn after death? Is it immediately after death or some time after?
You do not know what you were before birth, yet you want to know what you will be after death. Do you know what you are now? Birth and rebirth pertain to the body. You are identifying the Self with the body. It is a wrong identification. You believe that the body has been born and will die, and confound the phenomena relating to the one with other. Know your real being and these questions will not arise.
Birth and rebirth are mentioned only to make you investigate the question and find out that there are neither births nor rebirths. They relate to the body and not to the Self. Know the Self and be not perturbed by doubts.