Legal assistance required

you have to apply at chennai as the posting place 

before filing give a formal letter to pay subsistance allowance and wait for there reply and after reply then file in the cat bench and for better lawyer you can search at the association of the CAT bench or the LCI search portal 

I am sorry but I do not under stand what could be "pay subsistance allowance" when he has beendismissed.  After dismissal theier is neither pay nor subsistance nor any further letter frolm employer.

You have to first of all submit appeal as per CDA rules of the PSU and then move to CAT ir the PSU is in the jurisdiction list .  If not then Distt court or High Court as considered appropriate by your advocate.

you have time to move to court.  You visit CAT(PB), hear arguments and consult an advocate appearing competent.

please also refer to earlier thread at https://www.lawyersclubindia.com/forum/Cat-jurisdiction-77263.asp#.UcnGN9jQzmk