Can itr of A.Y 17-18 be revised ???

law of to assessment year 2017-18 revised return can be filed up to 1 year from the end of the relevant assessment year or before the completion of assessment whichever is earlier.
So the last date of revised return for the assessment year 2017-18 was 31st March 2019 subject to completion of assessment.

For AY 2017-18, last date to file revised returns is 31.3.2019 as per amendment

Yes you can revise
Last date for revise return is 31.03.2019 and before completion of assessment if any, whichever is earlier