There are 3 option to reset or get new passward for ITR e-filling
1. If old ack. no. is available in your record of any a.y. filling
2. If security question answer available, which is entered during new registration
3. If both ack no. as well as sec. question not available, then call to income tax customer care no. 0120-2438000 & tell the problem, give all particulars related to PAN Database- like PAN No., Name, Father Name, Date of Birth, Address E-Mail Id & Mobile/Phone No. etc, the customer executive process your query & resolved after 24 hrs.