I have heard that applications created in .net can be run on linux and other operating system using mono framework. Up to what extent it is true.
How it makes an application platform independent. How monoframework recognizes dll's of .net
How can i host my site created in asp.net to be hosted on linux server. What all softwares do I need if it is possible.
See this, is it the same thing I am looking for. It is talking about creating services rather than hosting
mono is an open-source implementation of the .NET run-time, along with open-source tools for the C# language (and VB.NET to some extent). You ask how mono can run .NET apps--the answer is that mono (mostly) runs just like Microsoft .NET, with the exception of a subset of supported libraries and APIs.
Take a look at mono's site for details about hosting ASP.NET apps on the mono runtime, and also MoMA (the mono migration analyzer) to inspect your .NET projects for mono compatibility.