Can ao ask information relating to other ay.

Assessing officer can ask for previous year figures, but cannot do detail varification of figures like sales purchase expenses income assets of A.Y other than the A.Y for which the notice u/s 143(2) is served. 

assessing officer can only demand information pertaining to transactions took place in the financial year whose notice was served upon the assessee...for eg he cannot demand the bank statements or itr for opening balance of unsecured loan or cannot added these transactions as they were assessed earlier...

for the previous years he can issue 142(1). He can complete the assessment 142(1) rws 143(3).

if the AO has doubts about the opening figures of Assets and Liabilities (mostly debtors and crediters) of present year, then he may seek the information of tranaction details about these accounts, for co-relation and verification.