Capital gains tax for property sale

Subrato (vp - ops) (30 Points)

18 December 2014  
I booked a flat in Mumbai in Oct 2009 and have been paying (a total of Rs1.45 cr ) for it on an Instalment basis due on per slab on completion. To date I have paid more than 90% of the value quoted by the builder. The project has got delayed and I am yet to receive possession for this property and pay a balance of 10 lacs outstanding which is due upon possession. However, I have already gotten this property registered in my name in June 2013. I have another property in Gurgaon which I want to sell for about RS 1.90 cr within the next 6 months and offset most of the Capital Gains against the purchase of the above property in Mumbai for which I'm yet to receive possession. Is this permissible and within the laws of Capital Gains?