Hi Deepa,
Firstly, are required to invest only the capital gain amount and not the entire sale proceeds.
Further, you can't invest in bonds now because time limit for investing in bonds is six moths from the date of sale of the old property.
Also, please note that if you can't purchase the property before July 2018, you will have to park the money equivalent to capital gain amount in cgds scheme, in order to claim exemption.
Please feel free to call/ revert in case you need more clarity.
Thanks and regards
Abhishek Dugar
CA CS B.Com