In FFVI is it possible to get the illumina and the rangnarok sword.

No.

In order to get the Illumina, you have to bet the Ragnarok at the Colloseum.
You win the Illumina, but you can never get back the Ragnarok.

i thought u stole a ragnorak from kefka at the end.... no wait that was atma weapon. Ragnorak... you trade eidolon for it right? if u bet it for illumina its lost forever. I never did get illumina - any good?

Well here's the thing, on my SNES game at least, you can cheat by sketching intangirs (or sometimes other invisible enemies) in the first world's triangular island. In doing this, I've gotten 255 Illumina Swords, so I actually had the Illumina and the Ragnarok equipped to one person (with a genji glove), just for fun.
But I don't think this works in the Playstation releases, under FF VI . But my oldschool SNES cartridge of the game lets me get LOADS of all kinds of stuff by sketching invisible things with Relm, the majority of which can be sold for soooo much GP. Be warned, sketching invisible creatures often results in really wacky results. Some characters will dissappear, some will be replaced by other things, everything goes fuzzy or blocky, and sometimes it just freezes. But if you get out of the battle (warp stones are handy for this!!), those 255 illumina swords are all yours.

There's a man in Narshe who lets you choose if you want Ragnarok as a sword, or as an esper.

The esper teaches you Ultima.

Like PT said, you bet the Ragnarok in order to obtain Illumina.

Also, generally speaking, trying to draw an invisible creature will just freeze up your game.

and f*ck up the saves so ive heard?

Originally posted by Ndi
Like PT said, you bet the Ragnarok in order to obtain Illumina.

Yeah, but I said that in another thread. :x

Also
it is possible to get both.
The second to last battle, you can steal Atma Weapon from one the sub bosses, and Ragnarock from the other.

Originally posted by hellfire_1234
and f*ck up the saves so ive heard?

YES.