Re validation of registration no.

Hi Friends, could you please tell me, whether I need to apply for re-validation of my CA Final registration no. before filling of exam form for Nov 2016,

My registration date to CA Final was 02/09/2011.

So in August (during filling exam form) I will have valid registration, but at the time of appearing in Nov it will be expired.

My question is should I revalid my Reg. No. before filling of exam form or I can do it after it expired (this is before appearing in exam).

Is there any online method of re-validating or only offline method?

Is the fees for revalidation of final registration is Rs.500 - can you plz confirm.

I have already cleared my Group -1 and going to appear in group-2 of CA final in Nov 2016.

Thanks in Advance.