Dear Sir,
It will be long term capital gain tax.
The date of acqusition is the date of allotment letter.
The tax between you and your wife will depend upon the fact that who has funded the property. If you have funded the property, it will be taxable entirely in your hands.
Please feel free to call/revert in case of any doubts
Thanks and Regards
Abhishek Dugar
CA CS B.Com