% 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://docs.db.ripe.net/terms-conditions.html

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

% Information related to '91.135.208.0 - 91.135.223.255'

% Abuse contact for '91.135.208.0 - 91.135.223.255' is 'abuse@mtu.ru'

inetnum:        91.135.208.0 - 91.135.223.255
netname:        RU-MTU-20061127
country:        RU
org:            ORG-ZM1-RIPE
admin-c:        MTU1-RIPE
tech-c:         MTU1-RIPE
status:         ALLOCATED PA
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         MTU-NOC
mnt-lower:      MTU-NOC
mnt-lower:      MR-Center-MTS-MNT
mnt-routes:     MTU-NOC
created:        2006-11-27T11:23:15Z
last-modified:  2016-05-24T10:41:12Z
source:         RIPE # Filtered

organisation:   ORG-ZM1-RIPE
org-name:       MTS PJSC
country:        RU
org-type:       LIR
address:        Smolenskaya-Sennaya sq., 27 bld 2
address:        119121
address:        Moscow
address:        RUSSIAN FEDERATION
phone:          +74957213499
fax-no:         +74992318129
admin-c:        LAP-RIPE
admin-c:        TABY-RIPE
admin-c:        LMUR-RIPE
admin-c:        YUF-RIPE
admin-c:        RPS-RIPE
abuse-c:        MAB8359-RIPE
mnt-ref:        RIPE-NCC-HM-MNT
mnt-ref:        MTU-NOC
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         MTU-NOC
created:        2004-04-17T11:55:44Z
last-modified:  2024-01-16T14:42:44Z
source:         RIPE # Filtered

role:           MTS backbone NOC
address:        PJSC MTS / former CJSC Comstar-Direct
address:        Petrovsky blvd 12, bldg 3
address:        P.O. BOX 4711 127051
address:        Moscow, Russia
remarks:        **************************************
remarks:        Contact addresses:
remarks:        routing & peering noc@mtu.ru
remarks:        spam & security abuse@mtu.ru
remarks:        mail postmaster@mtu.ru
remarks:        ddos reports ddos-reports@mtu.ru
remarks:        **************************************
phone:          +7 495 721-34-99
fax-no:         +7 495 956-07-07
admin-c:        EDA-RIPE
admin-c:        RPS-RIPE
tech-c:         EDA-RIPE
nic-hdl:        MTU1-RIPE
mnt-by:         MTU-NOC
created:        2002-10-18T13:29:19Z
last-modified:  2022-04-08T13:50:05Z
source:         RIPE # Filtered

% Information related to '91.135.216.0/21AS43720'

route:          91.135.216.0/21
descr:          Mobile TeleSystems, PJSC, Orel branch
origin:         AS43720
mnt-by:         MTU-NOC
created:        2018-06-25T15:38:11Z
last-modified:  2018-06-25T15:38:11Z
source:         RIPE # Filtered

% This query was served by the RIPE Database Query Service version 1.114 (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