Is it possible to use CIBlockSection::GetMixedList or GetList not in a component, but in the index.php of the page?

Question

1C-Bitrix

I have tabs in the index.php of the page whose content is made "bitrix:catalog.section", and the name of the tabs is the name of the subsections, I want to take them from the admin panel, how can I do this?

Answer 1

Do not mix questions in one.
If you separate them, you will understand that this is not a problem.

Is it possible to use CIBlockSection::GetMixedList or GetList not in a component, but in the index.php of the page?

Can.
Nobody directly forbids you to use classes outside of components. The main thing is that the necessary modules and the prologue are connected.
However, this violates one of the ideological concepts of the system. It is better to make a component.

I have tabs in the index.php of the page whose content is made "bitrix:catalog.section", and the name of the tabs is the name of the subsections, I want to take them from the admin panel, how can I do this?

In the same way as in any other component: through the API that is kindly supplied by the company.