registration no.

i m a pcc student n i wanted to know weather one registration no. is valid for 5 attempts of pcc or for 5 years from d date of registration for pcc......
i have already given 5 attemots of pcc....so i realyyy want to know weather i need to re-register myself or no...
i realyyy have no clue abt d same....
plss help me....n reply soonnn
thankssss....