when the term is still in use officially, how am i supposed to refrain from using it? because few internet posters tell me it is offensive?
You don't get it or failed to read carefully the posterst comments.
It is not because of few internet posters, rather, it is because the group the terms " Red Indians" apply to find it offensive.
The people whose opinion count the most are those directly affected, and they strongly object to it.
If, the people in India, currently called Dalit objected to the term and whish to be called by something else, then other should respect their wishes.
"Oriental" was once used to refer to all Asians, but no longer , people of Asian ancestry objected to the term, although the world can and is still being used w/o objection to apply to ther entities., such as oriental cusisne, oriental rug, oriental garden, oriental medicine.