anyone used any idea for capturing captcha in selenium
As below, the two are mutually exclusive. If Selenium could simulate a captcha, then it would allow robots to override the captcha mechanism (which is meant to exclude robots).
Two ways I've used:
Have a switch in the code to disallow captcha for Selenium testing.
Automate the rest of the test and enter the captcha manually - good article here using the "break" command.