Rancid Flesh is a goregrind band from Fortaleza, Ceará, formed in 2009. Their debut release Festering Gore... Repulsive Stench (2009) was pressed in a limited edition of 100 copies on Bidule Mandibule Records, and their 2012 follow-up Pathological Zombie Carnage — a 25-track album jointly released through Carnificina Records, Cianeto Discos, Terceiro Mundo Chaos Discos, and Rapture Records — was limited to 1,000 CDs.

Rankatoko is a thrash metal and hardcore band from São Paulo formed in 2019, with a lineup of Marcelo Viera on vocals, Eduardo Xaxa on guitar, Alex Souza on bass, and Eduardo Jamaica on drums. Their debut release, the three-track EP Chacina e Posse, was recorded live at Greenhouse Studio in São Paulo and released on January 20, 2019.

Ranterío is a groove metal band from Buenos Aires who released their debut album Agonía independently in 2016, followed by a second album, Hoguera de Miserias, around 2020. The band has been a fixture of the Buenos Aires underground metal circuit, including an appearance at Heresy Fest at The Other Place venue in the city.

Raped by Pigs is a brutal death metal band from Lima, Peru, formed in 2009 in the Breña district. Their sound draws from American-style slam and brutal death metal, with lyrical themes of torture, perversion, and horror. The band has released multiple recordings including the albums Squealing to the New World (2014) and Mental Diseases and Congenital Malformations (2019).

Raptore was founded in 2012 in La Plata by vocalist and guitarist Nico Cattoni, who relocated to Barcelona in 2018 and rebuilt the band with guitarist Jamie Killhead, bassist Cristian Blade, and drummer Ángel Smolski. The band released their debut album Rage N' Fever in 2016 on Total Desaster Productions, followed by Blackfire (2022) and Renaissance (2024) on German label Dying Victims Productions. During their South American years they opened for Exciter and Enforcer, and their sound draws comparisons to classic acts such as Liege Lord and Chastain.

Raptores is a thrash metal band from Ribeirão Preto, São Paulo, formed in 2010. They released their debut EP Forgotten Is Not Dead in September 2010 and followed it with the full-length Age of Fear in May 2012 on Genocidio Records, a ten-track album that incorporates thrash, death metal, and traditional heavy metal influences.

Rarmagom is a one-man symphonic black metal project from Santa Bárbara d'Oeste, São Paulo, operated by Clayton, who handles all vocals, guitars, and bass. The band previously recorded under the name Nuntius before adopting the Rarmagom name in May 2019, and that same year issued their debut demo The Cross Is Empty, but the Throne Is Not through Vision of God Records, a five-track release built around explicitly Christian lyrical themes.

Raskol is a one-man black metal and grindcore project from Recife, Pernambuco, created and run entirely by Bruno Kbça Nascimento. The project released three records in quick succession — Kvlt Skvm Krvst (April 2019), Perturbado (July 2019), and Um Rato (February 2020) — all of which sit in a raw, crust-inflected blackened grindcore style rooted in the DIY underground of Brazil's northeast.

Rat Hole is a sludge metal and grindcore band from Puerto Montt, Chile, formed in 2020. Signed to Horror Panda Records, the band has released a string of demos, EPs, and compilations since their debut, including the 2023 EP "Noisy Apocalyptic Shit" and the live album "Violent Osorno" in 2024. Their themes span political satire, drugs, and mental illness, earning them a self-described tag of "sludge from the south of Chile."