Regional InternetRegistries (RIR) are Network Information Centers(NIC) that operate regionally. The RIR organizations are five non-profit organizations worldwide that manage IPv4 and IPv6 IP addresses in the regional area via the Local Internet Registries (LIR).
The Regional Internet Registries (RIR) allocate Internet addresses to Internet service providers and local registries. The five Regional Internet Registries are AfriNIC for Africa, APNIC for Asia Pacific, ARIN for North America, LACNIC for Latin America and the Caribbean, and Réseaux IP Européens( RIPE) for Europe.
The Regional Internet Registries (RIR) were described in RFC 2050 and are intended to establish global guidelines, among other things. Each individual RIR organization is tasked with establishing local policies for managing the limited address space of IPv4 addresses. In addition, they are to maintain the Internet's routing tables, support Classless Interdomain Routing( CIDR), and support address manipulation.