Reapplying as a transfer

I was rejected from TUJ last year with a 3.33 GPA. I am now studying at another university and plan to apply again at the end of this semester. I should be able to finish with a minimum 3.6-3.7 GPA.

I was wondering should I apply when I finish this semester and have 18 credits, or wait until 30? I know that the point of waiting until 30 is so that they don't take into account your HS GPA, but I don't even think my HS GPA is too low for TUJ.. I don't really know why I wasn't accepted in the first place, considering many people requiring VISA with a lower GPA than my own got in.