Ca final may 2017 exam form

Hello everyone, I have a very urgent query, my initial Ca final registration expired on 05/10/2016 and I filed for revalidation in February 2017 and have yet to receive a response from ICAI for the same. Now I want to apply for CA final may 2017 exams, can I do it using my original Reg. No. ? What should I do? I don't want to miss this attempt. Please respond soon. Thank You in advance.