What is the procedure adopted for making the assessment under section 143(3) i.e. scrutiny assessment?
In case of Assessment under section 143(3), a scrutiny is carried out to confirm the correctness and genuineness of various claims, deductions, etc., made by the taxpayer in the return of income. The other procedures in this regard are as follows:

If the Assessing Officer or prescribed i​ncome tax authority considers it necessary or expedient to ensure that the taxpayer has not understated the income or has not computed excessive loss or has not underpaid the tax in any manner, then he will serve on the taxpayer a notice requiring him to attend his office or to produce or cause to be produced any evidence on which the taxpayer may rely on in support of the return.
The provisions of notice are governed by section 143(2). In other words, to carry out assessment under section 143(3), the Assessing Officer should serve a notice under section 143(2)​.
Notice under section 143(2)​ shall be served on the taxpayer within a period of six months from the end of the financial year in which the return is filed.
The taxpayer or his representative (as the case may be) will appear before the Assessing Officer and will place his arguments, supporting, etc., on various matters/issues as required by the Assessing Officer.
After hearing/verifying such evidence and taking into account such particulars as the taxpayer may produce and such other evidence as the Assessing Officer may require on specified points and after taking into account all relevant material which he has gathered, the Assessing Officer shall, by an order in writing, make an assessment of the total income or loss of the taxpayer and determine the sum payable by him or refund of any amount due to him on the basis of such assessment.​