Illegal termination

What exactly is your question?

if you are aggrieved by the termination order passed  by the school authorities then you can approach appropriate legal forum to get your grievances  redressed. 

You may consult a service law practicing lawyer in the local and discuss the matter and proceed as suggested to remedy for this.

Yes, what is the remedy that you are seeking?

Anyhow, if on probation, services could be discontinued based on performance of assessment, but not arbitrarily based on the alleged directions of the Chairman

If you feel aggrieved by the order passed by School authorities, you may move in School Tribunal of the State (if it is operative) otherwise to the jurisdictional court through a local prudent lawyer.

- In some states including Maharashtra, Delhi & U.P, there are state specific laws under which the remedy 
is avaliable. A teacher can intiate a suit.
- For other states, the remedy is appraoch the high court under a writ petition challenging such termination.
- Only ad-hoc (appointed for a specific purpose) can seek civil remedy if there is a contact. 
- In any case, all the documents including salary slip, communication, proof of service etc are required and can 
be sufficient in proving the case. 
- Absence of a formal appointment letter is not fatal if other credible evidence (ID card, PF/ESI, salary slips, 
manager’s letter, oral testimony) is presented and corroborated.