If you mean you need a host that provides both IIS and Oracle, that's a tall order. The Oracle wiki lists several companies that can host an Oracle database, and those companies probably also host Microsoft servers that can be configured as Web servers:
http://wiki.oracle.com/page/Oracle+Database+Hosting+Companies
Of course, if you're willing to buy all the software licenses needed, you can set up your own dedicated or virtual dedicated servers, either at godaddy.com or rackspace.com or the like.
If you mean you have an Oracle database you can make available to your Web app (that is, you'll allow inbound connections from the Web app to your own database server running Oracle), well, that's easier to do; any old ASP.NET host should do just fine.
