Hello,
first: welcome to the forum!
I think it's a Pattani carita blade. Others with much more knowlegde than I am will jump in and will give you a a more accurate opinion.
Look here for example for a very similar bilah:
http://www.vikingsword.com/vb/showth...ghlight=carita
Can we see the complete keris?
Regards,
Detlef