Job termination without any Notice

Sir, yesterday i got an mail from my school and that was an termination latter. When i see that latter i was shocked and they terminate me in this Covid-19 pendemic situation whitout any notice. I write the words below used by management department of my school in termination latter. To, Mr. XYZ Sub: Regarding the Termination of your services. Dear Sir We regret to inform you that you are terminated from services as a teacher in our educational institution. It has been decided by the Management due to your poor teaching skills which have led to your student’s low percentage score. We are sorry to inform you that we are not satisfied by your service. We request you to complete the No Dues Form as soon as possible. We wish you best of luck for your future. They terminate me without any notice and they said i was terminated due to poor teaching skill...they never talk about my teaching skills...and now in this lockdown period they claim that i was terminated due to.my poor teaching skill even then not an single parent complain against my teaching skill. I hope you got it what I'm trying to say.So now please tell me how i take further steps to make complain against them and which type of proof helps me in labour Court to prove my case.