Maybe yes. If you ask them i'm pretty sure they might. If not then you would proberply need to give them a percentage of the money you make if it ever did become commercial. Also some of the people who made the tilesets may not be active or even play jj2 anymore. nor leave any trace of contact. So it all depends like cooba said.

And a big no to epics tilesets if it was commercial.

Edit: also what game are you makeing could you give us/me some info i'm intrested.