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

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://apps.db.ripe.net/docs/HTML-Terms-And-Conditions

% Note: this output has been filtered.
%       To receive output for a database update, use the "-B" flag.

% Information related to '176.237.0.0 - 176.239.255.255'

% Abuse contact for '176.237.0.0 - 176.239.255.255' is 'abuse@turkcell.com.tr'

inetnum:        176.237.0.0 - 176.239.255.255
netname:        TR-TURKCELL-20111201
country:        TR
org:            ORG-TIHA1-RIPE
admin-c:        TIM96-RIPE
tech-c:         TIM96-RIPE
status:         ALLOCATED PA
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         tr-turkcell
mnt-routes:     tr-turkcell
mnt-domains:    tr-turkcell
created:        2015-09-10T12:19:57Z
last-modified:  2016-11-23T07:49:13Z
source:         RIPE # Filtered

organisation:   ORG-TIHA1-RIPE
org-name:       Turkcell Iletisim Hizmetleri A.S
country:        TR
org-type:       LIR
address:        Aydinevler Mah. Inonu Cad. No:20 Kucukyali Ofispark Maltepe
address:        34854
address:        ISTANBUL
address:        TURKEY
phone:          +902164581000
fax-no:         +902164275060
admin-c:        IS349-RIPE
admin-c:        RG9555-RIPE
admin-c:        TIM96-RIPE
mnt-ref:        RIPE-NCC-HM-MNT
mnt-ref:        tr-turkcell
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         tr-turkcell
abuse-c:        TAH47-RIPE
created:        2005-05-04T13:21:19Z
last-modified:  2023-04-18T09:16:08Z
source:         RIPE # Filtered

person:         Turkcell IP Manager
address:        Turkcell Kartal Plaza
address:        Topselvi Mahallesi Dipcik Sokak No:31
address:        Kartal ISTANBUL
phone:          +90 216 458 10 00
fax-no:         +90 216 427 50 60
nic-hdl:        TIM96-RIPE
mnt-by:         tr-turkcell
created:        2006-04-17T07:04:48Z
last-modified:  2011-07-17T21:19:30Z
source:         RIPE # Filtered

% Information related to '176.237.0.0/19AS16135'

route:          176.237.0.0/19
origin:         AS16135
mnt-by:         tr-turkcell
created:        2019-05-20T13:24:01Z
last-modified:  2023-03-10T07:05:34Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.111 (ABERDEEN)

Search for
IP address lookups			Miscellaneous queries
-l	1st level less specific		-i	Inverse attributes	None admin-c admin-c,tech-c,zone-c author cross-mnt cross-nfy local-as mbrs-by-ref member-of mnt-by mnt-lower mnt-nfy mnt-routes notify nserver origin person referral-by rev-srv sub-dom tech-c upd-to zone-c
-L	All less specific		-T	Object types	All as-block as-set aut-num domain filter-set inet-rtr inet6num inetnum irt key-cert mntner peering-set person role route route-set rtr-set
-m	1st level more specific
-M	All more specific		Query hints Include "AS" in front of an AS number. Example: AS4808 Include "-t" (template only) or "-v" (template and description) in front of an object name to view the template Example: -t inetnum
-x	Exact match only
-d	Associated reverse domain