The Celigo Magento connector does not import tax from Magento to NetSuite when creating Sales Orders. The tax configuration in both NetSuite and Magento need to match in order to ensure that tax will be calculated correctly on both sides.
For NetSuite to compute taxes, the items need to be set as taxable, as well as the customer. NetSuite will then perform a lookup of the appropriate tax percentage to be applied. If either the customer or the item is not set as taxable, then it would not apply tax which may result in a tax variance. The connector will record the tax variance under the Magento tab of the Sales Order.