A Veracrypt volume on a SAMBA mount can not be mounted because Samba only gives necessary permissions to the authenticating SMB user while Veracrypt tries to mount as the local root user. To get around this, it is necessary to mount the remote Samba volume locally as root

For example,

sudo apt install cifs-utils
sudo mount -t cifs //192.168.3.1/MyBookA b2-crypt/ -o user=sagar,password=foobar

Then, the volume is available in the b2-crypt folder