Best Registeel counters are Chandelure, Moltres, Entei, Heatran, Blaziken and Charizard. Registeel counters are heavily based its Fire-type weakness, but you can use Fighting and Ground type counters as well.
Registeel Raid Boss is a Generation
A guide on how to counter Team GO Rocket Grunts in Pokemon GO. Includes Pokémon lineups for all Grunt fights. Updated for December 2020. Team GO Rocket Grunts can be quite difficult without proper counters, especially if you’re using a