Hello Student
The formalities for attending the next slot for counselling if any Student fails to attend any prior slot for counselling Student has to should seek permission for attending the next slot for counselling.This prayer should be made to the related authority with required documents as proof of unavoidable reason that you have failed to attend the prior slot booked by the Student himself.
As you were not able to attend the prior slot of TS Eamcet counselling so you have to take permission  of the authority on the same way.
Hope this helps.