Rectification Of Mistake apparent from records

Rectification order can be passed only by the officer by whom the order was passed. So u will have to apply to the Assessing officer only.

Dear my question is that can an A.O. made an application for rectification to CIT (Appeal)..?

Yes it can be done

(2) Subject to the other provisions of this section, the authority concerned—

             (a)   may make an amendment under sub-section (1) of its own motion, and

             (b)   shall make such amendment for rectifying any such mistake which has been brought to its notice by the assessee, and where the authority concerned is the ⁹²[***] ⁹³[Commissioner (Appeals)], by the ⁹⁴[Assessing] Officer also.

thnx...

and can u also tell me that what is the time limit for passing an order u/s 154.

As per section 154 

(7) Save as otherwise provided in section 155 or sub-section (4) of section 186 no amendment under this section shall be made after the expiry of four years⁹⁸[from the end of the financial year in which the order⁹⁹ sought to be amended was passed.]

(8) Without prejudice to the provisions of sub-section (7), where an application for amendment under this section is made by the assessee on or after the 1st day of June, 2001 to an income-tax authority referred to in sub-section (1), the authority shall pass an order, within a period of six months from the end of the month in which the application is received by it,—

             (a)   making the amendment; or

             (b)   refusing to allow the claim.

So application can be made within 4 years and order should be passed within 6 months of the application.

And u can thank by using the thank user icon also. 

this 4 years limit includes 6 months Limit....?

No. Four year limit for application and rectification order must be passed within 6 months

DEAR SIR

PLEASE TELL ME ONE MORE THING THAT , WHAT ARE THE CONSEQUENCES  IF THE INCOME TAX AUTHORITY DOES NOT PASS RECTIFICATION ORDER WITHIN THE SPECIFIED PERIOD

CAN YOU PLEASE REFER ANY HIGH COURT AND SUPREME COURT CASES PERTAINING TO THE ISSUE CONCERNED