Interest on refund u/s 244a

I have filed ITR-4S on 4th Aug  under 139(5) revised return

I have refund which is 10% more than the Tax

I have claimed TDS which is not seen yet on 26AS but my client have given challan nos. 

My query is

1) Whether I will get interest on refund from April 1st  2017 or  4th August 2017

2) In case my return is assesed  and there is a demand bcoz of missing tax credits

   Will i get Refund on demand  after i rectify the return when Tax credits appear in 26AS

I am attaching 244A  amendment. for your all experts to comment.