police verification not required for license conversion.
it might be required for the flight school in india where you do your indian skill tests. depends on the flight school. some need it some don't.
clarify it with them when you book your skill tests and also clarify what all documents they will need from you for issuing the SPL.
SPL is required along with RTR and FRTOL for doing the skill tests. the school gives you spl but rtr and frtol has to be in hand before you go to the school.