Validity of registration for CA

it is clear in the announcement itself, only those students whose period is expired have to apply to revalidate their registration.

this 5 year registration  begins from when = after you begin your PE1 OR CPT / after you begin your articles? A student gives 2 attempts within his articleship period of CA final (in case he clears pe2 or pcc in 1st attempt) So you mean for 3 attempt validation of registration is needed?

the period of regiestration starts from the date of registration into the relevant level i.e. cpt , ipcc and final. means period of reg. for ipcc starts from the date when u got registered after clearing the cpt and for final after clearing the ipcc level.