Pay for Norton 360 Deluxe but get that coverage on one and Internet Security on the other. NOTE: 360 Deluxe covers up to 5 machines

I have two iMac desktops: 2012 and 2021. Norton Internet Security run on the 2012 model, but it needs an entire new operating system in order to run Norton 360 Deluxe.

My question is: can I subscribe to Norton 360 Deluxe for the new model… and only be billed for that coverage (up to 5 machines) but run Norton Internet Security on my older model?

I don’t have anything laying around to backup my old hard drive before installing the new operating system and that’s what Apple recommends. I don’t use that computer on the net hardly at all, so I’d rather not go the New Operating System route, but I don’t want to pay for 2 subscriptions as I have been for the last 3 years.

Does Norton do that? Pay for one package but use an older product for part of it?