Hello aspirant. Cut off by tamilnadu state board will be prepared by taking only group subjects score in 12th and 11th. As in maths or computer science, physics and chemistry. The score will be made out of 200 Mark's. So for a student of tamilnadu, a score of 196+ would fetch a seat in good university. If you wish a really good branch like cse or ece,  have a cut off of 198 plus. Then you donot need to look back.

Hope this helps

All the best

Regards

Nikhitha