Which has weight a republic act or an implementing rules and regulations?

A Republic Act (RA) holds more weight than its Implementing Rules and Regulations (IRR) because the RA is a law passed by the legislative branch of government, while the IRR serves to provide detailed guidelines for the enforcement of that law. The IRR cannot contradict the provisions of the RA; it must operate within the framework established by the law. Ultimately, if there is a conflict between the two, the Republic Act prevails.