After Resignation Till When We Can Pull Our Paper Back In Wipro

Hi,
i want to know after giving resignation in wipro, till when i can pull back my resignation.
Actually i got a new job but the new company want me to join within 50 days and wipro's notice period is 60 days, and the new company don't want to extend the joining date, as before only i told them that i can join within 50 days because they are not ready to give 60 days. I just accepted the offer from there end and latter i didn't told them that i have to serve all 60 days.
so please give me your suggestion, as i had already resigned and waiting for good time to talk to my new company to extend my joining.

In continuation of above, in view of the Apex court decision in Srikantha SM v Bharat Earth Movers Ltd decided on 7.10.2005 the resignation can be withdrawn till resignation is accepted by employer and the employee is relieved.
Thanks
Sushil