I have written a script to start a virtual machine through pass through mode and port number.

I start the guest linux through Run command from windows
telnet <baseIP> <portNUm>

Then after connecting to that guest machine,

each enter taking twice.

Any help will be greatful

Please read the "Question Guidelines" and "How to ask a smart question" links in my posting signature. You provide no details at all, which would let us help you. You don't post your script, tell us version/distro of Linux, what kind of virtual machine, what telnet client you're using on Windows, etc. With no details, there is nothing much we can tell you.

First place to check would be whatever terminal emulator you're using, and see if "local echo" is turned on, and turn it off if it is. The second thing to do would be to NEVER USE TELNET...it's old and insecure, and not used for VERY good reasons. Use SSH instead.

Can you post the script???
The question does not provide much details to solve the issue.