The missing number should be 1,

First row contain square of 17 (289)

Second row contain square of 18 (324)

So the third row may be square of 19 (361) where 1 is missing number.

Another possibility can be made out of this :-)

Last column is the sum of 2nd column and (1st colum -1)

9=8+(2-1)

4=2+(3-1)

?=6+(3-1)

?=8

:-)