Give a way by which validation rule is bypassed while uploading through Salesforce Data Loader.

Hi saurabh,

Yes. Create a checkbox field as API upload and make this field hidden in page layout. Create a validation rule and in evaluation criteria first check if checkbox is false and then check other validation criteria.
Whenever user upload record through data loader, specify value for this checkbox as true in .csv file and then upload it to salesforce. While upload, validation rule will fire and will find checkbox value as true so it will not check other criteria and system will allow to upload records.

Thanks.