Manasa, I think you're getting confused with 2 entirely different products here. 10g introduced a new product called DBConsole, with which you can access a database & administer it via a URL - this is what you are getting when you type in: http:\\local_host:1381\em\console

What you need to do is exactly as pareshjavkar has said, which is to install the client version of OEM. (Sorry, pareshjavkar, didn't want to hijack your good advice, but just wanted to explain things to Manasa a bit better.)