Can i consider leather products tahir or not, from the following countries:

China
India
Brazil
Portugal
Italy
Turkey
and other non muslim countries as there are little percentage of muslims living there. So can we give probability to those leather products and use it? I'm buying all these products from UAE.

Please give the criteria for considering tahir to the leather products made in kafir countires.

The criteria is products of Muslim countries where the majority of its people are Muslims and the producers of the leather are most likely to be Muslims, for example Pakistan, Afghanistan, Iran, Iraq, Turkey, Azerbaijan, Syria, ect.
From the countries you mentioned, only Turkey's leather should be treated as tahir. Even if you buy these products from Dubai (Muslim country), as long as you know that it's produced by none Muslims, it's not tahir.