Lost BSNL Mobile Prepaid Sim Card

Hi,
I've lost my BSNL prepaid sim card ironically at my bro's home. Where should I call to block that card? Will I have to lodge an FIR for the Sim Card misplaced at home? Remember that I've not lost the mobile handset.

I understand that I'll have to apply for a duplicate sim card at the BSNL office if I want the same number. Is that correct?

Yes, you need the ID / Address proof to apply for the duplicate SIM. It will cost you Rs. 200/- plus ST.

yes you can get a new sim at the cost of Rs. 200 and the older sim will be automatically blocked..

Thank you for your suggestions. I'm glad to update that yesterday my bro found the Sim Card in his drawer. Delighted to get it back as it has more than Rs. 1000 credit. :-)