Yes. You can apply RTI for a copy of the guidelines for collection of toll fee to National Highways Authority of India (NHAI).
National Highways Authority of India was set up by an Act of the Parliament, NHAI Act, 1988 and hence is a public authority under Section 2(h) of the RTI Act 2005.
To know the further procedure to file RTI Applications for Central Government Departments please refer https://onlinerti.com/how-to-file-rti-online-for-center