Hey Gowtham, 

I want to inform you that , TNEA does not  give preference to any boards but use a method called normalisation. Im which , if 

• a student A secured highest marks in maths in state board of tamil Nadu which is 100 and the highest marks scored by student B in the same subject is 90 but from different state board , both of them would be considered as 100 . 

• a student A got 70 marks in chemistry where as the first marks in the same subject and the same board is 95 , then , A's marks will be considered (( 70/95)*100)  75.78 .

Hope it has answered your queries.

Thank you