Telecom Regulatory Authority Of India - Subsection
Section 16(5) in The Telecom Consumers Protection and Redressal of Grievances Regulations, 2007
(5)The appellate authority may call for, any information, document or record, from the service provider referred to in clause (b) of sub-regulation (2) or the appellant, which may be relevant and necessary for examination and disposal of the appeal, as the case may be.
