Dear Mohan,
You can apply for the TS-ECET even after you have completed your diploma from Hyderabad. But you have to be a domicile of either the state of Telangana or Andhra Pradesh.
So, if you have a domicile of Andhra Pradesh you can apply for it.
I hope this will solve your query.
Good luck.
College Comparison based on Courses, Placement, Rank, Fee
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile