Employees' State Insurance (General) Regulations, 1950
56. Time of granting medical certificate
(a) An Insurance Medical Officer shall give the medical certificate to an insured person at the time of the examination to which it relates; where he is prevented from so doing he shall send the certificate to the insured person within twenty-four hours thereafter.
(b) No further medical certificate relating to the same examination shall be issued, except where a duplicate of such certificate is required, in which case it shall be issued free of charge and clearly marked "duplicate".