How to setup multi language team site classic view on SharePoint Online

Hello Rajeshlohar 

it's a long time ago, that i used this in classic, but i think, this links will help you. But im not sure, it works on M365 classic...

In classic you have the following options:

https://support.microsoft.com/en-us/office/choose-the-languages-for-a-sharepoint-site-user-interface-16d3a83c-05ab-4b50-8fbb-ff576a3351e8

And here are a very good blog, which language will be used in the MUI:

https://www.eliostruyf.com/demystifying-the-mystery-behind-the-ui-language-in-sharepoint/

Regards, Dave