% APNIC found the following authoritative answer from: whois.apnic.net

% [whois.apnic.net]
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% Information related to '202.136.176.0 - 202.136.191.255'

% Abuse contact for '202.136.176.0 - 202.136.191.255' is 'ap.eis-netops@global.ntt'

inetnum:        202.136.176.0 - 202.136.191.255
netname:        NTTS-SGP-AP
descr:          NTT Singapore Pte Ltd
country:        SG
admin-c:        NAA7-AP
tech-c:         NAA7-AP
abuse-c:        AN734-AP
status:         ALLOCATED NON-PORTABLE
mnt-by:         MAINT-SG-NTTS
mnt-irt:        IRT-NTT-SG
last-modified:  2022-05-06T13:24:05Z
source:         APNIC

irt:            IRT-NTT-SG
address:        NTT Singapore Pte Ltd, 8 Kallang Avenue,
e-mail:         ap.eis-netops@global.ntt
abuse-mailbox:  ap.eis-netops@global.ntt
admin-c:        NAA7-AP
tech-c:         IE11-AP
auth:           # Filtered
remarks:        ap.eis-netops@global.ntt was validated on 2025-08-25
mnt-by:         MAINT-SG-NTTS
last-modified:  2025-12-04T01:00:18Z
source:         APNIC

role:           ABUSE NTTSG
country:        ZZ
address:        NTT Singapore Pte Ltd, 8 Kallang Avenue,
phone:          +000000000
e-mail:         ap.eis-netops@global.ntt
admin-c:        NAA7-AP
tech-c:         IE11-AP
nic-hdl:        AN734-AP
remarks:        Generated from irt object IRT-NTT-SG
remarks:        ap.eis-netops@global.ntt was validated on 2025-08-25
abuse-mailbox:  ap.eis-netops@global.ntt
mnt-by:         APNIC-ABUSE
last-modified:  2025-12-04T01:00:17Z
source:         APNIC

person:         NETWORK ADMIN - AS17645
address:        NTT Singapore Pte Ltd
                20 West, Pasir Panjang Road
                #11-28, Mapletree Business City, S117439
country:        SG
phone:          +65 6871-5403
e-mail:         ap.eis-netops@global.ntt
nic-hdl:        NAA7-AP
mnt-by:         MAINT-SG-NTTS
last-modified:  2025-07-01T09:56:01Z
source:         APNIC

% This query was served by the APNIC Whois Service version 1.88.36-SNAPSHOT (WHOIS-AU5)