Benefit of claim of Section 54 exemption in case of Sale of residential Property

Mr. X has a residential house property in Lucknow and Pune, both are in the joint name of Mr. X and Y. Of these properties Owners decided to sell Lucknow property and purchase another house in Pune. Upon sale of Lucknow property Mr. X and Y earned capital gain of 45 lacs. are they eligible to get claim on purchase of new house Pune under Section 54 of Income tax, if not then what's the best way to plan this capital gain?