First Appeal is the statutory remedy available to the RTI Applicant, when there is no response from the Public Information Officer within stipulated time limit or the decision of PIO is not satisfactory or the PIO offered / supplied incorrect / misleading information or demanded exorbitant further fee etc. The First Appeal is required to be filed under Section-19(1) of RTI Act.
Section 19(6) of the RTI Act provides that the first Appellate Authority should dispose off the appeal within thirty days of the receipt of the appeal.
You can file First Appeal to the First Appellate Authority for an unsatisfactory response from the PIO within 30 days of the reply received.