Can I use the same domain I use in Microsoft 365?

[Rohith3132]

My organisation is having a Microsoft 365 subscription. The domain we use was purchased from a different web hosting provider. 
We are in need for Google Workspace now. We can't do a full Migration as we need Microsoft 365 too.

My question is "Can I use the same domain that I use for Microsoft 365 to buy Google Workspace subscription?"

Let's say our domain name is testdomain.us which was bought from a web hosting provider (Not Google or Microsoft). 

1. Can I use testdomain.us to Sing up for Google Workspace?
2. Should I buy a different domain like testdomain.ca? (Let's say my organisation has a branch in Canada) 
3. If I follow method 1, can I route my emails to outlook? 

Please recommend me the best method 
Thanks 

[StephenHind]

@Rohith3132 Yes, you can use the same domain for both services! Sign up using your existing domain and then you can if you want your email to go to Google Workspace or keep it with Microsoft 365.  The other services (e.g. Drive, Docs, etc) don't care where the email goes.