Here is a list of all macros with links to the files they belong to:

N_COLS : aesb.c
N_EXPECTED_FIELDS : timings.cc
NAME : pointertest.cpp
NAT_CHAIN_TYPE : nftnlrdr.c
NATPMP_NOTIF_ADDR : natpmp.h
NATPMP_NOTIF_PORT : natpmp.h
NATPMP_PORT : natpmp.h
NEED_CMP_CLONG : mdb.c
NELTS : ringct.cpp
NET_BUFFER_LOG : buffer.h
NET_MAKE_IP : net_node.inl
NEW_CONNECTION_TIMEOUT_LOCAL : abstract_tcp_server2.inl
NEW_CONNECTION_TIMEOUT_REMOTE : abstract_tcp_server2.inl
NEXT_LOOSE_PAGE : mdb.c
NF_CONNTRACK_LOCATION : nfct_get.c
nf_nat_multi_range : tiny_nf_nat.h
NFT_DESCR_SIZE : nftnlrdr_misc.h
NODE_ADD_FLAGS : mdb.c
NODEDATA : mdb.c
NODEDSZ : mdb.c
NODEKEY : mdb.c
NODEKSZ : mdb.c
NODEPGNO : mdb.c
NODEPTR : mdb.c
NODESIZE : mdb.c
NOHDR : mdb_load.c
NON_RESPONSIVE_PEER_KICK_TIME : cryptonote_protocol_handler.inl
NONCE_POINTER : slow-hash.c
NOT_OPTIMIZED : argon2_core.c
NOTIF_NEW : minissdpd.c, printresponse.c
NOTIF_REMOVE : minissdpd.c, printresponse.c
NOTIF_UPDATE : minissdpd.c, printresponse.c
NTS_SSDP_ALIVE : minissdpd.c
NTS_SSDP_BYEBYE : minissdpd.c
NTS_SSDP_UPDATE : minissdpd.c
NUM : assembly_generator_x86.cpp, instruction.cpp, instruction_weights.hpp, jit_compiler_a64.cpp, jit_compiler_x86.cpp
NUM_BLOCKS_PER_CHUNK : blockchain_utilities.h
NUM_METAS : mdb.c
NUMKEYS : mdb.c