@JohanSolo
Thanks for your time to answer my question.
I am unable to control the encoding of the CSV File. The CSV file can be created from any of the spreadsheet applications.

If you're on Windows it's most likely any other encoding but UTF-8 which will be used by default. Better check (and set if needed) manually the encoding before trying to import the data in your program.

QTextCodec::setCodecForLocale(QTextCodec::codecForName("UTF-8"));

I have also tried setting the codec to the text stream. My source code for reading the csv file and listing in a QTableWidget is as follows:

void csvfileDialog::on_btn_listfile_clicked()
{
    QString data;
    QFile importedCSV(ui->txt_csvfilename->text());
    QStringList rowOfData;
    QStringList rowData;
    if(ui->txt_delimiter->text().trimmed().isEmpty())
        ui->txt_delimiter->setText(",");

    data.clear();
    rowOfData.clear();
    rowData.clear();
    if (importedCSV.open(QFile::ReadOnly))
    {
        QTextStream csvstream(&importedCSV);
        csvstream.setCodec("UTF-8");
        data = csvstream.readAll();
//        data = importedCSV.readAll();
        rowOfData = data.split("\n");
        importedCSV.close();
    }
    else
        return;
    rowData = rowOfData.at(0).split(ui->txt_delimiter->text().trimmed());
    ui->tab_csvlist->setColumnCount(rowData.count());
    ui->tab_csvlist->setRowCount(rowOfData.count()-1);
    for (int x = 0; x < rowOfData.size(); x++)
    {
        rowData = rowOfData.at(x).split(ui->txt_delimiter->text().trimmed());
        for (int y = 0; y < rowData.size(); y++)
        {
            QString tempstr = rowData.at(y);
            qDebug()<<tempstr.toUtf8();
            ui->tab_csvlist->setItem(x,y,new QTableWidgetItem(tempstr));
        }
    }
}

Unable to understand where am I wrong.