Yes, a doctor can use a sign board. However, the MCI Code of Medical Ethics Regulations, 2002 have prescribed criteria for the information to be carried on the sign board in section 7.13 as follows:

7.13 MCI Act: It is improper for a physician to use an unusually large sign board and write on it anything other than his name, qualifications obtained from a University or a statutory body, titles and name of his speciality, registration number including the name of the State Medical Council under which registered. The same should be the contents of his prescription papers. It is improper to affix a sign board on a chemist’s shop or in places where he does not reside or work.