(a)the Assessing Officer shall, in respect of such search or requisition, issue a notice to such person, requiring him to furnish within a period specified in the notice, not exceeding sixty days, a return in the form and verified in the manner, as may be prescribed, setting forth his undisclosed income, for the block period, and––(i)such return shall be considered as if it was a return furnished under section 263 and thereafter notice under section 270(8) shall be issued;(ii)any return furnished beyond the period allowed in the notice shall not be deemed to be a return under section 263;(iii)no notice under section 280 is required to be issued for the purpose of proceeding under this part;(iv)a person who has furnished a return under this clause shall not be entitled to furnish a revised return;(v)the time allowed for furnishing a return under this clause may be extended by a further period of thirty days, where—(A)in respect of a tax year immediately preceding the tax year in which the search is initiated or requisition is made, the due date for furnishing the return has not expired prior to the date of initiation of such search or requisition;(B)the assessee was liable for audit under section 63 for such tax year;(C)the accounts (maintained in normal course) of such tax year have not been audited on the date of issuance of such notice; and(D)the assessee requests in writing for extension of time for furnishing such return to get such accounts audited;