Hi @kiranta
It is indeed not possible to manage BIOS settings from MAAS as @r00ta mentioned, however if you have BMC controller that supports Redfish, you can try customising built-in commissioning script that does BMC configuration or craft your custom commissioning script.
Some BMC controllers do support PATCH: /redfish/v1/Systems/1/Bios
https://www.dmtf.org/sites/default/files/Redfish_School-BIOS_Configuration.pdf
E.g. Supermicro should support this according to the manual