Actually ....
It comes with IE 11. It just isn't the default.
@iSlax,
I hope you are using the loader to run it.
How did you install Win10? Did you upgrade Win7 or 8.x?
Or did you do a clean install?
Are you running on a physical machine or on a virtual machine?
Were you able to run the Rohan client on THAT machine before upgrading it?
Is your internet cable plugged in on the machine you are running Rohan on (don't laugh. it happens. A Lot)
If you have ever played on private servers, your Windows\System32\Drivers\etc\hosts file may have been updated to block calls to the rohan servers. check it.