As @terdon stated in his comment, `.bashrc` is relevant only for users using `bash`. This is because the file is sourced when `bash` is launched.
To achieve what you want to do, the easiest solution is to add the option `-u` to the line that reads something like
`Subsystem sftp /usr/lib64/misc/sftp-server`
in `/etc/ssh/sshd_config`. For example :
`Subsystem sftp /usr/lib64/misc/sftp-server -u 0002`
See `man 8 sftp-server` for details.