"Has anyone ever sent data serially to visual basic6 through the serial port using an 8051 microcontroller."

These are two completely independent issues:

1. Sending data from the 8051.
All the 8051 "knows" is that it's sending data out of its serial port - it doesn't know (and doesn't care) what might be connected at the other end of the line.
This has been discussed here ad tedium - look at 'Tutorials' & 'Code Library', and use the 'Search'

2. Receiving data from a PC COM port in Visual BASIC.
Again, alll the VB "knows" is that it's receiving data from of a COM port - it doesn't know (and doesn't care) what might be connected at the other end of the line.
VB programming is, of course, off-topic.