Hi,
Yes, you can create a linked server to Oracle from SQL Server. Please refer the following article -
How to set up and troubleshoot a linked server to an Oracle database in SQL Server - http://support.microsoft.com/kb/280106
Also, the following article would be helpful:
Setting Up an Oracle Linked Server - http://www.sqlmag.com/article/sql-server/setting-up-an-oracle-linked-server49687
Hope this helps!
Shahfaisal Muhammed http://shahfaisalmuhammed.blogspot.com