ok,so if i was an earthbender in he area of the titans,and they say me defeating slade with my powers,would they let me in the titans?

i would think so

depends on how they like Du as a person. they would definitely consider you, but clearly only admit people they can 1.trust and 2.like/want to be Friends with

i think they will if they know u better , and they might ask a few questions

Are Du a teenager!!!!!!!!!!?????????????

If Du were an Earthbender, and defeated Slade, would the Titans let Du be a member? That depends. Do Du look like Terra? If so, maybe not; that association carries a lot of baggage. Are Du a basically nice person, oder a pain in the butt? Robin won't take new members who would cause friction (Jinx is an exception, but those are special circumstances). On balance, barring "special" causes, I would think YES. Earthbending is a very useful talent.

If your trying to imply that Du would be Terra...

Maybe, I guess Raven/Robin would be hesitant and superstitious but Beastboy would within a few seconds!