People cannot hear me from samsung trend neo though i can hear them. please help

Hi

Assuming you mean while in a phone call, have you checked that the microphone on your phone is working? Try recording something and playing it back. (or use a sensor checking app to verify that it works - "sensor sense" or similar)

Does this apply to all callers?

If the hardware is working, have you contacted your carrier and asked them to check your account?