capital gain

dear sir,

I am the direct allottee of this BDA property. Got allotted in 28/03/2003 but got registered in my name in 19/05/2005 PFA the sale deed, allotment letter and khata for your reference. There are no consturction or structure on this property, It is still a vacant land. Currently the property is under GPA in my dad’s name . I found a buyer for this property. He has agreed to pay 1.51 crore for this property. According to him the current book value of this property in this area (SMV Layout 3rd block) is Rs. 1300 per sft The book value may come around 50lakhs. So he is saying he can register the property upto 50 lakhs and remaning he will pay by cash. Planning to have the sale agreement by mid feb 13 and complete the registration by April 2013. I have following questions:

1) If I complete the registration by April 2013, what will be the capital gains on this property?

2) Since I have provided GPA to my dad, will the sale proceeds will come to me or this can be handled as my dad’s transaction?

3)what all exemptions available for vacant land?

4)how much tax should be paid?

Thank you