Ao's order giving effect to appeal order by cit appeals

The CIT Appeals has passed Appeal Order in October 2012 rejecting the disallowances made by AO. Till now the AO has not passed any Order giving efefct to the Appellate Order passed by CIT Appeals.

Now, is there any time limit for passing the Order by the AO under section 251 / 143(3) giving effect to the Appeal order ? What if there is a refund ?

Regards,