Section 54 of income tax act

I sold my residential house for Rs. 3000000/- in AY 2015_16 and deposit the sales proceeds in my Saving Account. In AY 2016_17, I purchase one Residential Flat with my Son and Daughter in Law. I invest Rs. 34 Lakh in that Flat as my Share. Is the amount taxable or under which section I can get relief i.e. Sec 54 or 54F or 54 EC. Which ITR I should used for AY 2016_17