The Bible seems to suggest that anyone who sincerely seeks God will find Him.
You will seek Me and find Me when you search for Me with all your
heart. Jeremiah 29:13 NASB
Even though this particular verse was written to a particular people, the principle could, perhaps, apply.
A very real way that God has and continues to respond to people in remote tribes who are seeking Him is the sending of missionaries. In his book, Eternity in Their Hearts, Don Richardson records actual occurrences where this has happened.
So, if this response from God is not excluded, then the answer is a definite "Yes, a person who has no access to the Bible or other Christians can still find Christ if he seeks God, because God can answer his seeking by sending him what he did not originally have."
If, however, this means of finding Christ is excluded, then the answer is definitely, "Maybe".
In the past decades, Jesus has been revealing Himself to Muslims at an alarming rate through dreams and visions, even the heart of Islam where Christianity does not even exist and no Bible is available. (See Which None Can Shut, Miracles Among Muslims, Dreams and Visions: Is Jesus Awakening the Muslim World, and I Dared to Call Him Father, to name a few). When these people experienced these dreams and visions, some of whom completely hated Christianity, they went in search of Jesus and found Him.
So, in these cases, people were not living in a remote tribe, but were, in fact, living in places where there were no Christians and no Bibles, yet they still found Christ.
For those people living in remote tribes, it is, perhaps, possible that Jesus could appear to them in similar fashion. We just can't know for sure.