How to file response to notice issued under section 143(2)?
​​​​If a return has been furnished under section 139 or in response to notice under section 142(1), the Assessing Officer or the prescribed income tax authority, as the case may be, if, considers it necessary to ensure that the assessee has not understated the income or has not computed excessive loss or has not under-paid the tax in any manner, shall serve a notice on the assessee requiring him on a date specified in the notice, either to attend the office of the Assessing Officer or to produce before the Assessing Officer any evidence on which the assessee may rely in support of the return.

Provided that no  notice under this sub section shall be served on the assessee after the expiry of 6 months from the end of the financial year in which the return is furnished.