16283 : order price is not a multiple of tick size

Try to place the Bracket Order, But the order is rejected. Please tell me the reason for this.

16283 : order price is not a multiple of tick size

Try placing order in multiples of tick size of 5 paisa on NSE.
For ex: If price is quoting at 100 then we should place order either at 100.05 or 99.95 but not at 100.01 or .02 etc.

I understood it should be .20, .25 like that,
but i can see some orders executed at .21, .23
how is this possible

It can’t be for NSE EQ and F&O, may be you are referring to average traded price or to some other segment.