Yes, your use of "on which" is correct here. When one refers to websites, the preposition used most often is "on".
Another example to illustrate this is, "The information can be found on our website, which is very well organised". Changing things around a little in order to use "on which", this would become:
"Our website, on which the information can be found, is very well organised."
To be clear, though, your initial use of "where" was not incorrect. You could use either. In this instance, however, I would suggest "on which".