Section 2 (g)defines “prescribed” as “prescribed by rules made under this Act by the appropriate Government or the competent authority, as the case may be;”
The rules apply to fees, formats for applications, appeals etc. These can only be made by the appropriate Government and competent authorities mentioned in Section 2 (e).
Other Public Authorities or departments have no authority to make any rules.
It is normally accepted that regulations also cannot go beyond what is authorised, For example, rules cannot specify exempting any information, beyond what is exempted under section 8 of the RTI Act.