Mantra: 5G NG-RAN consists of gNBs that utilize NR air interface and even ng-eNBs that utilize LTE air interface but connect to the 5GC.
Brief Explanation:
Formally, the 5G System (5GS) includes the User Equipment (UE), Next-Generation Radio Access Network (NG-RAN), and the 5G Core (5GC) (also known as Next-Generation Core (NGC)). A typical NG-RAN consists of next-Generation Node Bs (gNBs), which are Base Stations. The gNB communicates with 5G UEs using the New Radio (NR) air interface. The NG-RAN includes even the eNBs that communicate with UEs using 4G LTE air interface! Such eNBs, however, can communicate with the NGC and supports new 5G intra-network interfaces.