Hello Sidharth,
I will suggest you have a look at
this OTN article[
^]. It provides step by step instruction in migrating SQL Server database to Oracle using a Oracle provided tool called SQL Developer. This a Java based tool & will require a Java Runtime.
Now for the second part I will suggest you to download
ODP.NET[
^], again from OTN web site & use those DB drivers. Ofcourse as mentioned by Raul this will require a change in your application.
Regards,