I have two computers and my family members have more,six in all,in two countries.Can we install scrivener on all these computers?
I believe the answers you seek are here: https://scrivener.tenderapp.com/help/kb/purchasing-and-installation/can-i-use-my-license-on-more-than-one-computer
Basically, each licence you purchase will be for one platform in one household. As one example in the link is that a child being away at university would need a separate licence, I’d say your example of all those machines in two countries is a no-no.
Basically, you and any family members living with you can use one Windows licence on any Windows machine mainly based in your house, so you’ll probably need two licences in your circumstances.