I want to save my SSRS Report Based on the Parameters Passed. i.e. Am passing P1 And P2 as parameters so I want my SSRS Report name as P1_P2_ReportName.Xtension.
What you are asking is to be able to create a report name dynamically, which is not something that can be programmed, on download, say, from Report Manager. You can (although I've never tested this) possibly do this through a subscription using @ParameterName @ReportName. citation from msdn It's about the best you can do for now, and there's a link on the citation that allows for this feature to be voted up.
If you want to use that as a naming convention, yes you can do that.
If you want the parameters to show on the report you can do that too. You can add them to the title, a header, footer or anywhere you want on the report as an expression.
If you are talking about saving the report output using parameters in tge name... i don't believe you could enforce the behavior but you may be able to do it programmatically.
But if you want the report name (.rdl file name) to be dynamic and change as you select different parameters, then no, you can't do that.