Rama, TNEA is not an entrance examination. It is a counselling procedure for admission to Engineering courses to all the Participating Colleges affiliated to Anna University, based on the marks secured in their 10+@ in Physics, Chemistry and Mathematics. So if you want to study Engineering in any one of the Colleges affiliated to Anna University, you have to participate in their TNEA Counselling. Anna University will release its online registration for Candidates across India. Candidates have to fill in the application form and submit it. Once you register,  Anna University will open the document verification process. After successful document verification. the list of the eligible Candidates will be released. Candidates need to pay the counselling fees, which is mentioned in our page: https://engineering.careers360.com/articles/tnea-counselling#TNEA-Counselling-Procedure-2020 . Post this, Candidates need to fill in the choices of their preferential colleges and lock them. TNEA Counselling is held in 4 rounds. After selection of seats, the final allotment of seats will happen. Candidates can either accept and confirm the seat or reject it and participate in further rounds.

There is no entrance examination for TNEA. The selection is based on the merit list prepared from class XII board exams result (most probably PCM Marks are taken into consideration). The person scoring well will definitely goon the top of the list and as the marks decrease, so is their position on the list.