As far as I know, it's not forbidden nor restricted by country. However, you should consider that, as the service owner, you are responsible in front of OVH for any illegal activity on those servers. Finally, it's almost the same that happens on your dedicated servers where you sell hosting service.
The best way to resell OVH service(any, not only dedicated servers) is using the OVH API. It's a REST API which you can invoke from almost any programming language. Here's the documentation:
https://api.ovh.com/
It allows to place orders. But the order payment must be done manually. Check the "/order" path.