Clarification on sec 80 dd claiming

Hi,

I have a 4 year old kid who is disabled. For claiming exemptions under Sec 80 DD, seen the info that I have to furnish certificate issued by medical authority. I have already applied for medical certificate on November 1st 2014 and have been informed that it will take time. My question is
1. If I receive medical certificate before 31st march 2015, will i be eligible to apply for refund on the tax paid?
2. If I receive medical certificate after 1st Apr 2015, will I be eligible to apply for refund since I have already applied for certificate on Nov 1st 2014 or I will not be eligible?

Thanks
Venkat.