Where to find documents relating to Ottoman Empire or Turkish controlled Armenia

Hello everyone! I'm a Brazilian guy, from Rio de Janeiro. My great-great parents (one set of them) came to Brazil around the early 1920's (he was born circa 1900, she was born around 1910). They were ethnic Armenians, but their birthplace is listed as "Syria". According to my grandma, who is their granddaughter, her grandfather's lands were taken by someone (either the Turks or the Azeris, but I don't think she knows who exactly) and so they were both forced to emigrate.

Unfortunately they both passed away a long time ago, before I was even born (he died in 1980, she died around 1995, I was born in 2004) so I never got to speak with them. Their only living daughter, my great-aunt, doesn't know much either, as none of their children learned Armenian and I guess her parents never told her about where they lived, all we know is it was a small settlement. Any way I could try to track some documents down? All the ones I found on familysearch are here in Brazil.