Loudspeakers or public system should not be used in night between
Under Rule 5 of the Noise Pollution (Regulation and Control) Rules, 2000, use of loudspeakers /public address system is restricted in the following manner: The loudspeaker or a public address system shall not be used at night (between 10.00 p.m. to 6.00 a.m.) except in closed premises for communication within, e.g. auditoria, conference rooms, community halls and banquet halls.
Thus, the correct answer is '10 pm to 6 am'.