Tamil Nadu Government Holiday

Is it a question paper?  Is it an exam hall?  What is your problem? Your query is not a legal query.

It is only 3 national holidays i.e., 26th January, 15th August and 02nd October every year when entire country schools and organisations are closed. 

First file RTI Application to DEO seeking information from them on all your doubts.  The reply is authentic public record.

Then make a written complaint to DEO, specifically pointing out such violations stating such dates and enlist support of other teachers in your efforts.

Also, contact local registered Teacher's association and elected representative to State Council give such petitions to them.

Wait for their response.

Why don't you post the facts as well the context for the query?