How many Protocols does NetBIOS has ?

Netbios has three protocols using 4 (2 UDP + 2 TCP) Ports:
137/udp netbios-ns NetBIOS name service 138/udp netbios-dgm NetBIOS datagram service 139/tcp netbios-ssn NetBIOS session service (Windows NT)
445/tcp netbios-ssn NetBIOS session service (New Port used by Windows 2000, Windows XP and Windows Server 2003)

137/udp netbios-ns NetBIOS name service = Allows name resolution without using a WINS server.
138/udp netbios-dgm NetBIOS datagram service = Used by applications such as the Messenger service, the Browser service, and other applications that use the mailslots interface.
139 & 445/tcp netbios-ssn NetBIOS session service = Allowing file transfers, network printing, and remote applications such as Server Manager and User Manager to function. The session service a connection-oriented, sequenced, reliable communication between two machines. The datagram service is a connectionless, unsequenced, unreliable service. netbios-ssn compares to TCP as netbios-dgm compares to UDP. NetBIOS is one of those things that exists at various layers, depending on whose book you're reading. Since NetBIOS requires some type of network and transport, it isn't a layer 3 or 4 protocol again it depends which book your are reffering.