Windows Server 2012 R2 IIS 10 / HTTP/2
Solution 1:
No, IIS is a integrated part of the OS and can't be separately upgraded to a newer version. HTTP/2 especially isn't implemented in IIS, but in a kernel mode driver that is naturally only available in Win 10/2016.
Note: IIS 10 Express exists (and can be installed on that OS), but this is a testing/development server not meant for production use.