Please remember that what you think of as an 8051 chip is only 1% chip, and 99% software.
Wanting to ask an 8051 chip which version software is inside is not possible as such. It is not the 8051 but the software inside the 8051 which will have to be able to tell you what version it is. I hope that you understand: electrically you are communicating with an 8051, but when it comes to the features, possibilities and impossibilities, it all comes down to what features the software in it has to offer, because that is what you will be communicating with, not "the 8051"!

The only other way to get around this is by reading the program that is in the 8051 byte by byte and compare it inside your PC with what you expect to be there (this is called program verification). As stated, extracting a program from a chip may be illegal and is not recommended. Then again, if the manufacturer of the software had any sense, they will probably have "locked" the 8051 so you can't read the program bytes inside anyway.

You will have to learn from the people who developed the software how to get the software version from the program inside the chip because it can be quite product specific, if at all implemented (possible).