Simple process call to contact number of ts eamcet provided by board in official web site they ask mobile number and name and tell us registration number this is true i got hall ticket in this way

Call the helpline number given in the official website with your registered number for ts eamcet and ask for your registration number by providing your basic details

Hope this helps as it helped me 

How to find registration  number..????

Send my registrated number

I have lost my emails and registration id

Dear sunny, please CHECK your email that you used in filling an application form online because all the details regarding your application sent by EAMCET team in your mail or more information you can visit the official website of TS EAMCET https://eamcet.tsche.ac.in/TSEAMCET/EAMCET_HomePage.aspx.