1) Visit the url https://onlineservices.tin.egov-nsdl.com/etaxnew/tdsnontds.jsp and select challan number ITNS 280.
2) Select Tax Applicable (0021) Income-Tax (Other Than Companies).
(a) Select (300) Self Assessment Tax as type of payment.
(b) Select the mode of payment and the bank through which the payment has to be done.
(c) Enter your PAN number.
(d) Select Assessment Year (takes precaution here and re-confirms your selection).
(e) Fill your contact details.
(f) Enter captcha code and click on proceed.