Is it justified to prevent tribal people from staying away from core area of the forest against?

no it is not at all correct forest it is the home for them

if someone comes to your home and ask that you are supposed to leave your home....will you...no....

tribal people doesn't harm forest they actually save it..... when they clear land for agriculture they don't cut trees as we do they burn it and the ashes are sprinkle in to the land to make the soil fertile...