Roll number must be required to saw result .
if you forget your PIN No. than its not things to worry because result also see by use WRO (reg no.) instead of PIN No.
in all situation , Roll number must be needed ....
Following tips to recover
1) try to find out PDF document or other format in which u Download admit card
2) Try to contact your friends who same in your exam class .
at least you able to known your Series in which you follow
3)Try to Contact ICAI Student helpline number which given on website
4)Find out you exam question papers in which you must write exam roll number before starting paper writing .