Sale of shares of listed co. Capital gains

If one has sold shares of listed Co. to buy property resi House within 1 year to claim exemption u/s 54 but before filing return only 6 months have passed from the date of sale of shares. Does he have to file return and show capital gains or he can wait till 6 months not showing this capital gains in his return invest in resi House full consideration and claim exemption in next year's return. Kindly advice or guide.
thanks