possible there are Africans in india in many southern Asian countries (probably from slave trade)

I would say that slave trade isn't here so important as natural conditions. So many people from India are dark-skinned ...

in the phillipines they have mountain people native that they say are black

Of course they are black but probably not African.And if they are African it wasn't slave trade but the same story like with Australian Aborigens. Roots of course in Africa,but so long ago calling them Africans has no sense.