Hi Nomita,
Thank you for using Syncfusion Products.
We have tried the sample at our side for ImportDataColumn at our side and we could see the string values are left aligned and the numbers are right aligned in the generated excel file(by default in XlsIO). We have verified the sample with our latest version 9.4.0.62. We have attached the sample in this forum for your reference.
Please try the sample at your side and let us know if this helps you. If you still face the issue, please get back to us with the simplified sample to proceed further on this.
Please let us know if you require any further clarifications.
Regards,
Sridhar.S
ImportExport_c4055350.zip