Is it possible to discover the set of bitcoin addresses from a public key? I'm trying to find the set of bitcoin addresses from a public key associated with a user just to analyse this user transaction. Is there any way to derive/find all the addresses that have been generated by this public key so far?
Expanding shesek's comment as an answer:

The "SIN" key you're looking at, on a profile on bitrated.com, is a particular feature of that site.  These keys are not directly used for Bitcoin transactions at all, so you certainly can't discover addresses from them.

As for Bitcoin public keys, one public key generates one address; you cannot use a public key to compute other addresses belonging to that user.  (Though you might find other addresses that participate in transactions with the first one, and guess that they belong to the same person; but that's not proof.)  

If someone is using an HD wallet, there is a concept of a master public key, from which one can determine the public keys for many different addresses that the user might be using.  People usually don't share those if they value their transaction privacy.