If you are a breakout player and you notice that high and low are different than actual one. You are right we may have slightly different high and low as compared to Actual high and low of the Day.
This is because we provide real time data which updates almost every second or when a trade happens. But if there are multiple trades in 1 second ( like sometime when market move fast, nifty can have 100 to 200 trades executed in 1 second) then there can be slight difference in the high and low.
While our data is most suitable for most retailers. If still you feel that you need perfect High / Low data. You can go to costly Providers like Global Data Feed. Who will charge 4 to 5 Times higher than us but surely will give you matching High and low Data
Remember : No Low-cost data provider can give High / Low matching Data in 500 pm