That depends on if that is a k6/2 or a k6/3
If that is a k6/2, a comparable processor would be the Pentium 2 300. The k6/2's lack of on-die cache limited performance greatly, among othe things.
If that is a k6/3, a comparable processor would be the Pentium III Katmai 450 - 500. The k6/3 was an awesome processor that performed great.
So depending on those two things, you may have a great classic processor, or a crap classic processor.