I am trying to receive serial data(RFID tag id) from arduino
You must, therefore, have an Arduino running some code that sends data to the serial port. Too bad you didn't feel that showing that code was useful.
and display the information in visual basic 6.0's textbox.
You must, therefore, have a VB application that has a text box, some code to open the serial port, some code to read the serial data as it arrives, or after is has been buffered, and some code to copy that data to the text box. Too bad you didn't feel that showing that code was useful.
Can anyone help me.
Given what you've posted, help seems unlikely. Though perhaps you've now thought of something.