In section 153 of the Income-tax Act, in Explanation 1, with effect from the 1st day of June, 2011,--
(a) in clause (vii), for the word, figures and letter "section 245R,", the words, figures and letter "section 245R, or" shall be substituted;
(b) after clause (vii) and before the words "shall be excluded", the following clause shall be inserted, namely:--
"(viii) the period commencing from the date on which a reference for exchange of information is made by an authority competent under an agreement referred to in section 90 or section 90A and ending with the date on which the information so requested is received by the Commissioner or a period of six months, whichever is less,".