Agri Gold — lost my bond

I have lost my agri gold bond. It's maturity will be on 2018. I have paid it in 1998. I have the bond consumer and nominee name. How can i get the bond number. We have paid one thousand rupees in 1998. We will get one lakh rupees on maturity i. E. On 2018 november. But the company is not there at present. But we lost our bond. So we have to get bond number. How can i get it