God promised that there will be people represented from every ethnic group in Heaven.
This is an article about the ethnic group from Joshua Project that mentions this uncontacted tribe. The Sentinel live on the North Adaman Island. The Sentinel don’t allow any visitors in. After the tsunami in 2004 when the Indian government went to check on them, men came out with arrows.
The majority of uncontacted tribes live in the forests of Brazil and Peru. They don’t have the bible in their language. Christians must be careful making initial contact because of disease and other issues.
Pray that God softens the hearts of the Sentinel in India and the tribes in Brazil and Peru. Pray that the governments of Brazil and Peru block the forestry and mining industries from exploiting the land where these tribes live. Praise God for the his word in the bible. Praise God for Christian missionaries already doing the work overseas. Pray for discernment and bible translators to be sent out.