Choose two columns for same purpose or it should be two different columns?
If there are only 3 states for EmiAmount (and barring other complications that may need to be added) I would be inclined to use the EmiAmount (NULL, 0, >0) to define the state.

Why add a flag (which is duplicate information) if the data itself easily describes the state that you need to know?  

I greatly prefer avoiding adding duplicate data which must itself be maintained. And a single source of the status (the actual data) is all that you need. 

Of course, there may be complications unmentioned that could complicate matters.