Income Tax e-Portal has releases a new functionality to enable taxpayers to reply to submit response to any ITBA notice/document DIN not linked to PAN/TAN or Notice under Section 133(6) where user may not have an e-filing account of the entity to which notice is issued.

The new feature also allows taxpayers to view the submitted response or add new response to any ITBA notice/document DIN not linked to PAN/ TAN or Notice under Section 133(6) where user may not have e-filing account of the entity to which notice is issued.

Income Tax Department
In reply you have to submit all the required documents and information that the tax department is seeking. Moreover, if the notice is regarding your due taxes file it before the due date and if there is any error in the return file a revised return.