Itr processing - ay 1718

I have filed an ITR-2 since Aug'16, but till date it has not been processed nor any 143(1) has been received from the department. When i filed a grievance, the system replied that there is a mis-match of income as per 26AS and ITR filed, but there is no further communication from the department end.

What can be the probable course of action in this situation? Can i revise my ITR even after 31st March, in case i received my 143(1) beyond the appointed date?

Thanks.