Capital gain tax

Respected Sir,

I have sold my property on june/2011, which is purchased in 1962 subsequently the land is acquired by BDA and re-allotted in 2008-09 after collecting betterment charges. now my question is for calculating capital gain tax for which shall i take purchase cost as per 1981 (i.e., property registered at sub-registrar office highest price) or at the time of Re-allotment of site by BDA sub-registrar guideline value rate.

thanking you,

jayasimha