Raid battle tequirement has been changed for the fourth time. And now raid battle is available to almost all trainers around the world.
Pokémon GO‘s official twitter Niantic updated that trainers from Level 5 and above will be able to participate in Raid Battles at a wide variety of Gyms around the world.
Raid Battles are now available for all Trainers Level 5 and above at a wide range of Gyms around the world! https://t.co/tywlcdOynZ
— Pokémon GO (@PokemonGoApp) July 1, 2017
Trainers take note that there are push notifications now in place to notify you beforehand when a raid starts. This will be true for all the gyms that are in proximity to your location. If you control a gym in your locality you will receive a notification about 2 hours before a raid starts to pop and the raids begin.