Hey jaya ! Considering that you want to know the number of students who participated in first round of TNEA counselling 2018. Then the approximate figure for this is 7100. Out of 7100 ,  over 6k students participated on the first day of counselling.

To know more about TNEA counselling , follow the given link :

https://engineering.careers360.com/articles/tnea

Hope it helps!