T-6 is the size of the flange. Take a pic of where the exhaust enters the turbo with a tape measure and we can tell you if its T-4 or T-6 or larger. Any more pics would help. BB typically means Ball Bearing in the turbo world. BB are better than standard roller bearing style turbos.
Look on it and see if it has an A/R number on it. And how large is the exhaust outlet.
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