Section 154

Fr rectifying it,,u have to fila an appeal against the recfication order passed u/s 154.

if there is any mistake apparent in the order, u may again go for rectification....

It is a rectification order passes u/s 154 by the Assessing Officer. I think in your case the AO suo motto has made a 154 order. it is now for you to compare the same with the return filed and appeal to the higher authorities. 

Say if the 154 order was passed by ITO, make an appeal within 30 days to CIT (appeals), see section 246A for more details.