how we can find out sublist ids by the console?

You can use the chrome plugin `Netsuite Field Explorer`; if you need it actually in the console for whatever reason...

require(['N/record'], function (record) {
    var rec = record.load({
        type: 'yourrecordtype',
        id: 'id'
    });
    rec.getSublists() //array of sublist ids
})