whether permission required from Hon'ble CAT for REJOINDER

Dear Yogesh

Filing rejoinder is not only essential but primary requirement do defend one's case and for the same no permission is required if the same is filed on time but suppose if the same has not been filed and matter is fixed for ex-parte hearing then in that case you will have to file a petition of recalling ex-parte order as well as for filing rejoinder. In legal practice lot depends upon facts and circumstances of the case.