Caste certificate related case

You can approach administrative tribunals if they do termination. In case if you feel unjustice to you.

you company can not give you  termination letter without showcause notice. In that showcause notice you have to give your reply along with the fresh caste certificate. There after they will give you again a letter of termination. It is the process if the company violate the this principle and without opportunity then you can file a case at Administrative Tribunal or High Court. You have a good case and there is a 100% chance to win ( if that is a Govt. sector job)  

If termination is ordered, then you can file a w.p. in high court as you have strong grounds to win the case.

Let them issue a termination notice asking you to explain the circumstances, you may submit the fresh caste certificate pleading your innocence about the issue, if the authorities still are adamant then you can choose legal course of action for reliefs. 

Basically your faultthat you submitted defective certificate.  Now you are submitted a certificate which can haave prospective application.  You failed to submit a certificate valid on teh date of joining.

Yes you can be denied a reserved post after following procedure of SCN.

Better you may seek mercy of the authroities as in this case legal recourse may or may not fetch yu relief.