booking amount taxablity in the hands of an Individual seller

1) Assessee has come into agreement with a Builder for 35% share in constructed flats in exchange of his Land in 2007. 2) After Receiving Allotment letter from Builder , Assessee has received amount as advance against Agreement to sell from ultimate buyers for his 35% allotted flats in single payment of Rs 1.43 crore against 5 (five) Flats in AY 2013-14. During Assessement AO has charged Capital Gain(LTCG) on Rs. 48.68 lacs (after reduction of indexed cost) My question is that whether it should be taxable in the hands of assessee, Case:1- if it is not the business of assessee. Case:2- if it is business of the assessee, however in that AY 2013-14 assessee has not shown any such stock or construction cost because developer was seperate and amount was received only on Allotment Letter and aggreement to sell. Can we file revision application if asseessee has no tax liability. Currnt situation: Flat has still not completed and there is no conveyance deed or registry executed till dec,2016. Please suggest possible solution to fight against AO. Thanks Sandeep Singh