dear aspirant, after successfully completion of jossa 7 round councelling, if some seats in NIT's , IIIT's and CFTI's are left the CSAB holds the responsibility of filling those seats which are left after josaa councelling. the documents required are same as per josaa rules and norms. wait for the official CSAB website to come into action in such case. first let the CSAB website take the action and regarding your domicile certificate it is only requireed for your physical reporting in the alloted institute.