Hi
@Rajan
We are UK based so have never encountered the specific E6011RP model you have, but based on other models released in our region at the same time as your model I think the only way to hard reset the camera is to open the body of the camera (the Samsung bullets usually unscrew somewhere along the body, either at the front or near the base of the bullet) where you should then find a physical hard reset button.
Press and hold the reset button for 5-10 seconds for the camera to default back to factory settings, you should then be able to set the camera up from scratch with a new password.