Dear Atul,
I'm sorry but I tried to give you as many hints as possible to implement this functionality as efficiently as possible. But I'm afraid can't do the coding for you. If time allows I'll publish a wiki article some day with a step by step procedure to implement recurring activities in SAP CRM.
Thanks for your understanding,
Best regards,
Nicolas.
PS: the dates fields are greyed out because you changed the date profile. You should keep the same date profile and add date ZNSOC in it (or create another one, but with the same date types as the original one).