These entries are queried from radb.net using whois, you can try my project getting these.
:AS58590 route: 103.8.248.0/22 descr: route object for 103.8.248.0/22 origin: AS58590 country: IN mnt-lower: MAINT-AMTRON-IN mnt-routes: MAINT-AMTRON-IN mnt-by: MAINT-AMTRON-IN last-modified: 2012-06-25T06:06:42Z source: APNIC rpki-ov-state: valid route: 103.8.248.0/24 descr: Assam Electronics Development Corporation Ltd origin: AS58590 country: IN remarks: www.amtron.in mnt-lower: MAINT-AMTRON-IN mnt-routes: MAINT-AMTRON-IN mnt-by: MAINT-AMTRON-IN last-modified: 2020-11-23T04:14:18Z source: APNIC rpki-ov-state: valid route: 103.8.249.0/24 origin: AS58590 descr: ASDC DR1 mnt-by: MAINT-AMTRON-IN last-modified: 2020-11-23T04:35:05Z country: IN mnt-lower: MAINT-AMTRON-IN mnt-routes: MAINT-AMTRON-IN source: APNIC rpki-ov-state: valid route: 103.8.250.0/24 descr: AMTRON Magicsurf Broadband Services origin: AS58590 country: IN remarks: www.amtron.in mnt-lower: MAINT-AMTRON-IN mnt-routes: MAINT-AMTRON-IN mnt-by: MAINT-AMTRON-IN last-modified: 2013-04-11T01:16:20Z source: APNIC rpki-ov-state: valid route: 103.8.251.0/24 descr: AMTRON Magicsurf Broadband Services origin: AS58590 country: IN remarks: www.amtron.in mnt-lower: MAINT-AMTRON-IN mnt-routes: MAINT-AMTRON-IN mnt-by: MAINT-AMTRON-IN last-modified: 2013-04-11T01:16:28Z source: APNIC rpki-ov-state: valid route6: 2403:bd00::/32 descr: route object for 2403:BD00::/32 origin: AS58590 country: IN mnt-lower: MAINT-AMTRON-IN mnt-routes: MAINT-AMTRON-IN mnt-by: MAINT-AMTRON-IN last-modified: 2021-12-14T12:53:24Z source: APNIC rpki-ov-state: valid