You should choose the course according to your passion and interest. Below are some of the courses which you can choose based on your interest

1- Engineering

2- Pure Science, Research & Mathematics

3- Medical

4- Marine/Defence

5- Fashion and Design

6- Humanities & Social Science

7- Law

Good Luck!!

Assuming you are asking for Medical entrances so the admission will be done through NEET score only as there will no separate entrance test in Tamilnadu. So if you want to get admission in Tamilnadu then you will have to clear NEET exam with more than 500 marks if you have the domicile of TamilNadu if not then more than 560 would be required for Govt colleges. To know all latest updates, you can stay tuned with us on below provided website -

http://www.medicine.careers360.com/

Hope this helps!!!