Ids scheme

My Client has sold Property at F.Y 2014-15. Result in a capital gain of rs. 20,00,000/- the original property was purchase 20 year back and was not book in the account. the capital gain was not disclosed in return file on a.y. 2015-16 can i declare this income under the income under the new disclose scheme ( Income Declaration Scheme 2016 ) and can i get benefit of indexing. kindly advise as soon as possible.