Long term Capital gains on selling plot

Sir, I ,a government servant ,jointly bought a flat along with my wife (50:50 share)in Bangalore and registered it in May 2006.The flat was sold in Mar 2017.The acquisition and sale values are as follows:- Acquisition Value-Paid to the Builder in May 2006 Registered value in Sales Deed Rs 11.33 lakhs(paid in cheque) Registration and Stamp Duty Rs 1.30 lakhs(paid in cheque) State Water &Electricity Board,Sanitary Services Rs 1.40 lakhs(paid in Cheque) Interiors Rs 1.15 lakhs (paid in cash with receipt) One time maintenance deposit to the Builder Rs 0.13 lakhs (paid in cash with receipt) Total Acquisition Value Rs 15.31 lakhs Indexed cost of Acquisition Rs 33.19 lakhs Maintenance cost incurred (Rs 1.025 lakhs) Building Sunk fund for maintenance collected by Association (2014-15) Rs 0.525 lakhs Building Sunk fund for maintenance collected by Association (2016-17) Rs 0.50 lakhs Indexed cost of Maintenance Rs 1.078 lakhs Grand Total of Acquisition Rs 34.268 lakhs Sales value(as reflected in sales Deed) Mar 2017 -Rs 41.5 lakhs(received in bank account of wife who is a house wife and no other declared income ) Difference (Sales value-Acquisition value)-Rs 7.232 lakhs Would be grateful if following queries can be clarified:- 1. Whether the inclusion of cost of one time maintenance amount and interiors charged by the Builder to Purchase value is in order. 2.Whether the inclusion of Building Sunk fund by association for maintenance of building in cost of maintenance is in order. 3.Since the Sales is done in Mar 17,do I have to buy GOI specified Infrastructure bonds for the full amount of Sales Rs 41.5 lakhs by 31 Mar 17 to get full exemption or can I join these schemes by 31 Jul 17(last date of filing returns) 4.In case the tax is to be paid ,which is the last date for paying tax of 20 % on the capital gains,i.e.,Rs 1.4464 lakhs (50 % each by my wife and self) without penalty? 5.Can I show the income gained 50:50 shared by self and wife in the respective tax returns for 2016-17? 6.Is there any embargo in expending the amount received from sales .can I use it for any emergency and replenish after say 0ne month prior filing returns/paying tax. 5.What is the best option available for reducing the tax burden in this case? yours sincerely Anand