Clarification on FDs

Hello sir... Request if anyone can guide me on the following issues. 1. My father had a Joint FD in a bank . Joint FD on the name of my father and grandmother. My father is no more.. so my grandmother becomes the sole owner of the FD. There is no nominee. My grandmother is bed ridden and bank guy says she has to come to bank to sign for adding a nominee or termination of FD. is there any other procedure to get her sign without going to bank ? Or any other procedure to add nominee without her sign ? Or any procedure to change the ownership of the FD. 2. What happens if my grandmother passed away and still there is no nominee of FD. ? How to claim the money ? Who can claim ? What's the procedure ? Pls guide me on this. Thanks