family tree

My maternal grandparents have a unique heritage each...
my grandmother was born a chinese and adopted by malays and late grandfather is pure javanese as he's parents were immigrants from java..

My late grandfather once said that he has family in jawa but its been a long time since they are seperated so they are unknown.. and just maybe the biological family members of my grandma are still alive and living in singapore..
i wanna embark on a mission, the mission to locate my unknown family members but the problem is i know nothing abt them.. haiszzz