how many bricks or stake needed to find an insert in them ??

not sure what you are asking.But don't assume every brick you get will have an insert in it...many searchers including myself have gone through many many dry runs with nothing showing up

every $5 brick have 100 notes

Actually a bundle has 100 notesA brick has 1000 notesA block has 4000 notesso a brick of $5 bills has a face value of 5KA block of $5 notes has a face value of 20K