Registering and activating your TAN (Tax Deduction Account Number) on the Income Tax Portal involves two separate steps:1. Registering your TAN:Visit the Income Tax e-filing portalClick "Register" on the homepage.Select "Others" and then choose "Tax Deductor and Collector" in the Category.Enter your TAN and click "Validate."If the TAN is valid and not already registered, proceed with filling out the basic details form.Enter details of the organization making payments or collecting tax.Verify and submit the form.You will receive a confirmation email and activation link.