Hi, gk2kandaiya,
I agree with ma_khan. If you can check your logs, that would be great. Running Failed Request Tracing would be even better: http://learn.iis.net/page.aspx/266/troubleshooting-failed-requests-using-tracing-in-iis7/. If you prefer not to do either of those, could you temporarily disable or uninstall first ARR, then BRT, to see which one seems to be blocking you? Which versions of BRT and ARR did you install, and which installation method did you use (download and run the MSI, or Web Platform Installer)? The more information you can share, the better we can help...
-Chris