to divisible by 90 it should be divisible by 9. hence the divisibility rule for 9 is the sum of individual numbers must be divisibe by 9 =.> 6+5+3+x+y should be divisible by 9 As 6+3=9 it can be removed then x+y+5=9 or its divisible one hence x+y=4 is the least possible individual numbers
4 would be the right answer.
Here because we can see - 10*9=90
Hence the no should also be divided by 10 and according to divisiblity rule of 10 the no conatains 0 at one's place is divisible by it. So in the given question 653XY, Y must be 0. According to divisiblity rule of 9, the sum of digits should be divisible by 9.
Hence 653X having sum of digits as 14+X, which is near to 18 because 18 is divisible by 9. So value of X+Y=4+0=4