If possible, try to disassemble trans and find out exactly which parts are needed. If not too much damage inside, perhaps you can just replace broken parts? Look them up on on line fiche if you can.
If bad internal damage then you'll need (possibly) a entire engine. (very hard to find and $$$$$ to ship to Chile) If that is the case, then best to part out bike for junk and walk away.
As Gipper says, Pre '96 is totally different bike. No compatibility far as I know.
Go onto a few DR650 sites (and DR threads) ASK for help! Also, contact Pro Cycle in Oregon. Ask if they can help out sourcing parts.
ProCycle have lots of DR bits and pieces and a lot of knowledge.
Trans failure on the DR have happened to quite a few riders. If internal damage is not bad, then repair may be possible. Several guys have done it,
replacing only damaged gears and such.
Ask for help here:
www.DRRiders.com
This is a DR650 specific forum, some of same folks as ADV Rider thread shown below.
the DR650 thread - ADVrider
The ADV Rider link above is a HUgE thread in Thumpers section, (over 100,000 posts) but very helpful DR guys, lots of DR knowledge, parts and more ideas. Just post up and ASK FOR HELP!
You will have to join above forums to post questions (free to join).
Good luck!