Penalty clause given by developer

Dear Sir

I have purchased a flat from Agarwal Associated Ltd. a Developer in East Delhi developing a group housing Project at Sector-76 by the name "Celebrity Homes". The developer has delayed the possession by more than 1 year. There is a penalty clause of Rs. 5/- sq.ft.

Is there any judgment of any Court of Law which has such reference by which the developers are entitled to pay only Rs. 5/- as penalty clause and 6 months as extension period.