Runescape is client sided, so you cannot change the game client in any way.
For example, in combat arms, you download the files, and if you wanted to mod your m16 to look like a ump, you could do that, On runescape, you don't download the game file, so you couldn't hack the game to give you 2147m (max cash) or 100 p-hats.
Runescape Botting is different. It does things differently. It isn't hacking, but still is against the rules. Change the RS2 hack section to the RS botting section