Hello yasudhar,
Thank you for contacting us about using FTP with FileZilla to upload files to your subdomain. When you create a subdomain, it creates an additional FTP account for access to the files.
You can view the FTP settings in cPanel at any time:
Click the Configure FTP Client link to the right of the account you want to login with , and you will see your settings displayed.
You can also use your cPanel username/password for FTP, since it has access to all files in your account, including the subdomain.
Thank you,
John-Paul